•   HEXLIBRISHV, 


WORKS  OF  CAPTAIN  H.  E.  CLOKE 


PUBLISHED    BY 


JOHN    WILEY   &   SONS 


The  Gunner's  Examiner. 

Third     Edition,    Revised    and    Enlarged.       8vo, 
viii  +  206  pages,  109  figures.     Cloth,  $1.50. 

The  Enlisted  Specialists'  Examiner. 

8vo,  vi  +  186  pages,    146  figures.      Cloth,   J2.00 
net. 


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THE 


GUNNER'S  EXAMINER 


PREPARED   BY 


HAROLD    E0    CLOKE 

Captain  Coast  Artillery  Corps,  U.  S.  A, 


THIRD   EDITION,  REVISED  AND   ENLARGED. 
FIRST   THOUSAND 


NEW   YORK 

JOHN    WILEY    AND    SONS 

LONDON:   CHAPMAN   AND    HALL,   LIMITED 

1908 


Copyright,  1905,  1906,  1908, 

BY 

HAROLD  E.  CLOKE 


Robert  Drummmtii  and  (Company 


PREFACE. 


OWING  to  the  practical  impossibility  of  a  student  of  gunnery 
obtaining  ready  access  to  all  the  books,  pamphlets,  circulars, 
orders,  etc.,  necessary  to  fit  him  for  the  examinations  as  required 
by  General  Orders  of  the  War  Department  for  first-  and  second- 
class  gunners,  and  also  owing  to  the  extreme  difficulty  the  average 
enlisted  man  has  in  comprehending  the  technical  language  in 
which  these  books,  pamphlets,  etc.,  are  couched, — provided  he 
does  by  some  stroke  of  good  fortune  come  into  possession  of 
some  of  them, — the  author  has  been  impelled  to  compile  this 
work. 

Effort  has  been  made  to  eliminate  all  subjects  that  are  not 
included  in  the  requirements  of  G.  O.  141,  1904,  yet  being  par- 
ticular that  it  contain  all  such  subjects  as  an  examining  board 
might  fairly  construe  to  be  within  the  interest  and  scope  of  the 
order. 

As  the  art  of  gunnery  changes  from  year  to  year,  and  the 
scope  of  gunner's  examinations  changes  likewise,  it  is  intended 
that  this  book  be  revised  and  published  accordingly. 

The  preparation  of  this  book  was  suggested  to  the  author  by 
the  members  of  his  company — the  6ist  Coast  Artillery. 

As  is  well  known,  the  first  publication  of  a  text-book  is  liable 
to  contain  a  few  technical  errors.  The  author  will  be  grateful 
for  any  information  of  such  a  character  concerning  this  work. 


362480 


IV  PREFACE. 

The  author  is  indebted  to  Brigadier- General  William  Crozier 
for  supplying  him  with  many  pamphlets  issued  by  the  Ordnance 
Department;  to  First  Lieutenant  W.  K.  Moore  for  correction  of 
proof  and  other  matters;  and  to  Master  Electrician  C.  M.  Beer, 
Artillery  Corps,  for  photographs. 

FORT  TOTTEN,  N.  Y.,  February,  1905. 


PREFACE    TO    THE  SECOND   EDITION. 


IN  this  edition  the  author  has  endeavored  to  make  all  the  cor- 
rections which  were  suggested  to  him  during  the  past  year,  and 
to  add  to  the  book  descriptions,  etc.,  of  the  new  range-board,  the 
deflection- board  several  later  types  of  guns,  and  a  brief  discourse 
on  the  loading,  planting,  and  care  of  submarine  mines  according 
to  the  new  and  adopted  system. 

The  author  desires  to  thank  Captain  R.  P.  Davis  for  his 
revision  of  the  "torpedo  gunnery"  contained  in  the  work. 

FORT  TOTTEN,  N.  Y.,  November,  1905. 


PREFACE  TO  THE  THIRD  EDITION. 


As  was  stated  in  the  preface  of  the  first  edition,  this  book 
will  be  revised  from  year  to  year  as  the  rules  of  gunnery  change, 
and  this  revision  is  made  merely  to  bring  the  book  up  to  date. 

It  is  intended  in  this  revision  to  conform  strictly  to  G.  O.  105, 
1907,  and  to  add  to  the  book  only  such  matter  as  will  assist  en- 
listed men  of  the  Coast  Artillery  Corps  to  pass  their  examinations 
for  first  or  second-class  gunners. 

The  chapter  on  submarine  mining  is  almost  completely 
revised,  for  the  reason  that  the  new  system  has  undergone  many 
more  radical  changes  within  the  past  few  years  than  has  gunnery 
in  the  Coast  Artillery. 

Several  additions  in  mortar  gunnery  have  been  made  in  order 
to  keep  pace  with  the  rapid  and  remarkable  development  of  this 
arm  of  Coast  Artillery. 

FORT  TOTTEN,  NEW  YORK, 
March,  1908. 


CONTENTS. 


CHAPTER  I. 

PAGE 

EXTRACTS  FROM  G.  O.  105,  MAY  n,  1907 i 

Schedule  of  Examination  for  Gunners 2 

Syllabus  of  Examination  for  Gunners 3 

Second-class  Gunners 4 

First-class  Gunners 6 

Torpedo-company  Gunners 9 

Examination  for  Second-class  Gunners 1 1 

General  Information n 

Service  of  the  Piece 1 1 

1 2-inch  B.  L.  R.,  Disappearing  Carriage 13 

12-inch  B.  L.  R.,  Mounted  on  Non-disappearing  Carriage 26 

8-inch  Non-disappearnig 30 

1 2-inch  Mortar,  Model  1896 33 

6-inch  Disappearing 37 

NOMENCLATURE  AND  GENERAL  DESCRIPTION 41 

Breech-blocks,  Recoil-cylinders,  etc 44 

Care  of  Guns  and  Carriages 66 

Powders,  Projectiles,  Primers,  and  Fuses 73 

Cordage,  Blocks,  Tackle,  Gins,  Shears,  etc 88 

Knots  and  Hitches .    91 

Splices 95 

Rigging-tackles 96 

Gins 98 

Shears 99 

Hydraulic  Jacks -. 102 

U.  S.  Magazine  Rifle.  Description  etc 105 

vii 


vm  CONTENTS. 

CHAPTER  II. 

PAGE 

EXAMINATION  OF  FIRST-CLASS  GUNNERS m 

(a)  The  Azimuth  Instrument  and  Definitions m 

(6)  The  Plotting-board 116 

The  Range-board 1 23 

The  Defiection-board 1 28 

The  Telescopic  Sight 136 

Wind  Component 145 

The  Aeroscope 146 

Anemometer 149 

Electric  Stop-watch 149 

The  Atmosphere -board 1 50 

Special  Apparatus  for  Mortars 151 

Battle-ships,  Armor,  etc 151 

EXAMINATION  FOR  TORPEDO-COMPANY  GUNNERS 169 

Second-class  Gunners 169 

Service  of  the  Piece,  Nomenclature 169 

Duties  in  the  Loading-room 174 

Duties  on  the  Water 181 

Magazine  Rifle,  Description,  etc 186 

First-class  Gunners  . .    186 

Care  and  Preservation  of  Mine  Material 186 

Handling  High  Explosives 189 

The  Azimuth  Instrument  and  Plotting-board 190 

Storage  Batteries 190 

Generators 190 

Searchlights 190 

Oil-engines 195 

Apparatus  and  Operation  of  Casemate  Switchboard 198 


THE  GUNNER'S   EXAMINER. 


CHAPTER  I. 

EXTRACTS  FROM  GENERAL  ORDERS  NO.  105,  WAR  DEPARTMENT, 
WASHINGTON,  MAY  11,  1907. 

144.  A  candidate  to  be  eligible  for  qualification  as  first-class 
gunner  must  have  previously  qualified  as  second-class  gunner, 
though  both  qualifications  may  be  made  at  the  same  examination. 

145.  Boards  of  examination  shall  be  convened  annually  in 
each  artillery  district  by  the  district  commander,  to  meet  within 
one  month  after  the  expiration  of  the  indoor  instruction  period. 
Separate  boards  may  be  convened  for  the  examination  of  candi- 
dates for  first   and  second-class  gunners  and  also  for  the  posts 
attached  to  the  artillery  district.     All  boards  shall  consist  of  three 
artillery  officers,  selected  with  reference  to  their  special  quali- 
fications for  this  duty;    provided,  that  when  a  member  of  the 
board  is  a  company  commander  he  will,  during  the  examination 
of  candidates  from  his  company,  be  replaced  by  an  officer  of 
another  company.     Where  travel  is  necessary  the  selection  of 
an  officer  for  this  duty  will  be  made  subject  to  the  approval  of 
the  authority  competent  to  order  the  necessary  journeys. 

146.  Each  company  commander  will,  previous  to  the  com- 
mencement of  the  examination,  submit  to  the  adjutant  a  duly 
signed  list,  in  the  triplicate,  giving  the  full  names,  arranged  in 


2  THE   GUNNER'S  EXAMINER. 

muster-roll  order,  of  all  the  men  in  his  company  who  are  to  be 
examined  for  first  or  second-slass  gunners,  with  the  statement 
that  he  believes  that  each  man  so  presented  is  capable  of  qualify- 
ing in  the  class  designated.  These  lists  will  be  transmitted  to 
the  senior  member  of  the  board  by  the  post  commander. 

147.  In  determining  the   qualifications  of   candidates   credit 
shall  be  given  for  practical  knowledge  of  subjects  rather  than  for 
text-book  answers  to  questions. 

SCHEDULES  FOR  EXAMINATIONS  FOR  CANDIDATES  FOR  GUNNERS. 

148.  For  candidates  in  companies  assigned  to  gun  defence: 
For  second-class  gunners — 

(a)  Service  of  the  piece 25 

(b)  Guns  and  carriages 25 

(c)  Powders,  projectiles,  primers,  and  fuses 25 

(d)  Cordage,  gins,  shears,  jacks 15 

(e)  U.  S.  magazine  rifle 10 

100 
For  first-class  gunners — 

(a)  The  azimuth  instrument 20 

(b)  Duties  in  the  plotting-room 50 

(c)  Aiming  and  laying  guns  and  mortars 15 

(d)  Elementary  gunnery 5 

(e)  War-ships 10 

100 

149.  The  examination  of  candidates  for  first-class  gunners  of 
organizations   assigned   exclusively   to   rapid-fire   guns   not   pro- 
vided  with    separate   position-finding   system    shall    include   the 
following  head  in  lieu  of  that  given  above  under  (b) : 

(b)   Subcaliber  firing 50 

150.  The  examination  of  candidates  for  first-class  gunners 
shall  be  held  as  far  as  practicable  at  such  places  as  the  material 
or  equipment  pertaining  to  the  subject  in  hand  is  located,  i.e., 
at  the  guns  or  in  the  plotting-rooms. 


EXAMINATION  OF  CANDIDATES   FOR  GUNNERS.  3 

151.  The  examination   in  subjects   (a),   (b),   (c)   for  second- 
class  gunners  and  in  subjects  (a),  (b),  (c)  and  (d)  for  first-class 
gunners  shall  be  confined  to  the  material  of  the  battery  and  its 
accessories  to  which  the  company  is  assigned.     If  no  azimuth 
instrument  is  included  in  the  battery  equipment,  the  instrument 
used  in  the  company  instruction  shall  be  used  in  the  examination. 
If  for  any  cause  beyond  the  power  of  the  battery  commander  any 
part  of  this  equipment  has  been  removed  from  his  control  and 
has  not  been  available  for  instruction  for  at  least  two  months 
previous  to  the  examination,  such  material  shall  form  no  part  of 
the  examination. 

152.  For  candidates  in  companies  and  detachments  assigned 
to  mine  defence : 

For  second-class  gunners — 

(a)  Ammunition,  nomenclature,  and  service  of  guns  as- 

signed to  the  company  of  which  the  candidate  is 
a  member 15 

(b)  Material  of  and  duties  in  the  loading  room  (except 

electrical  principles  involved) 35 

(c)  Material  for  and  duties  on  water 30 

(d)  Cordage 10 

(e)  U.  S.  magazine  rifle 10 

100 
For  first-class  gunners — 

(a)  Care  and  preservation  of  mine  material 20 

(b)  Handling  high  explosives 20 

(c)  Knowledge  and  use  of  the  azimuth  instrument  and 

plotting-board 20 

(d)  Batteries,  generators,  and  searchlights  assigned  to 

the  company  of  which  candidate  is  a  member 20 

(e)  Apparatus  and  operation  of  switchboard  and  care 

and  use  of  telephone 20 

100 


4  THE  GUNNER'S  EXAMINER. 

153.  The  qualifying  mark  for  classification  as  first  -or  second- 
class  gunner  shall  be  in  each  case  not  less  than  an  average  of 
75  per  centum.     Whenever,  during  the  progress  of  the  examina- 
tion of  a  candidate  for  either  grade,  the  sum  of  the  marks  received 
on  subjects  in  which  he  has  already  been  examined,  increased 
by  the  maximum  allowed  for  the  remaining  subjects,  is  less  than 
75,  his  examination  will  be  discontinued. 

154.  Instruction  in  the  course  for  first  or  second-class  gunner 
will  be  given  to  such  men  as  the  company  commander  may  con- 
sider capable  of  mastering  the  prescribed  schedules. 

155.  Men  not  receiving  instruction   in  the  gunners'   classes 
will  perform  such  duties  at  their  batteries  or  elsewhere  during 
the  hours  for  instruction  as  their  company  commander,  with  the 
approval  of  the  post  commander,  may  direct. 

156.  The  board  shall  keep  a  record  of  its  marks  during  the 
examination,  but  these  marks  shall  not  be  published  in  orders. 
The  record  of  each  company  shall  be  sent  to  the  artillery  district 
commander  as  soon  as  possible  after  the  completion  of  the  ex- 
amination,  to   be   published   immediately.     The   report   of   the 
board  to  be  published  in  orders  shall  contain  the  names  of  those 
who  have  qualified  as  first  and  second-class  gunners  and  recite 
the  date  of  the  report,  which  will  be  the  date  of  the  completion 
of  the  company  examination  in  each  case,  the  names  being  arranged 
for  each  organization  in  each  class  in  muster-roll  order. 

SYLLABUS  OF  EXAMINATION  FOR  CANDIDATES  FOR  GUNNERS  IN 
COMPANIES  ASSIGNED  TO  GUN  DEFENCE. 

The  following  syllabus  gives  the  outline  of  the  scope  of  the 
examination  of  candidates  for  gunners  in  companies  assigned 
to  gun  defense.  While  the  indoor  instruction  in  any  subject 
need  not  be  limited  to  what  is  indicated  in  this  syllabus, 
the  examination  of  candidates  for  gunners  shall  be  confined 
thereto. 


EXAMINATION   OF  CANDIDATES  FOR  GUNNERS.  5 

SECOND-CLASS   GUNNERS. 

(a)  Service  of  the  Piece. 

Questions  on  the  service  of  the  piece  and  nomenclature  of 
the  piece  to  which  organization  is  assigned.  If  the  company  is 
assigned  to  pieces  of  different  calibers,  the  candidate  will  be 
examined  upon  the  piece  of  the  caliber  selected  by  the  company 
commander.  Examining  boards  are  cautioned  not  to  attach  too 
much  importance  to  nomenclature,  where  a  candidate  shows 
a  knowledge  of  the  practical  use  of  the  part  under  examina- 
tion. 

(b)  Guns  and  Carriages. 

Explain  briefly  how  a  breech-block  of  a  heavy  gun  or  mortar 
is  dismantled;  having  a  breech-block  completely  dismantled  (not 
dismounted),  how  it  is  assembled  and  adjusted  for  firing;  how 
old  packing  is  removed  from  recoil-cylinders,  and  how  they  are 
repacked;  how  recoil-cylinders  are  filled.  Object,  care,  and  use 
of  throttling-valve  for  guns  and  by-pass  valve  for  mortars.  Parts 
and  surfaces  of  guns  and  carriages  to  be  oiled;  how  much  oil  to 
use,  and  how  it  is  used.  Adjustment  of  grease-cups.  In  the 
case  of  rapid-fire  guns  explain  how  to  adjust  firing  mechanism, 
percussion,  and  electric  (if  so  equipped). 

(c)  Powders,  Projectiles,  Primers,  Fuses. 

Examination:  Name  the  kind  of  powder  used  in  the  pieces 
of  battery  to  which  organization  is  assigned;  give  the  weights  of 
service  charges  and  corresponding  muzzle  velocities  of  these 
pieces;  also  the  lowest  and  highest  muzzle  velocities  of  the  steel 
and  cast-iron  mortars,  if  assigned  to  mortar  battery.  Name  the 
projectiles  used  in  the  pieces  and  give  their  weights.  Tell  how 
to  distinguish  from  the  painting  of  projectiles  used,  its  kind, 
armor-piercing  quality,  and  nature  of  bursting  charge.  Point 
out  the  cap,  the  ogive,  the  bourrelet,  the  body,  the  base,  the 
rotating  band,  the  fuse  hole  of  a  projectile. 

Name  each  kind  of  fuse  used  in  the  battery  (ring  resistance, 
centrifugal,  combination,  detonating,  see  Ordnance  Department 


6  THE  GUNNER'S  EXAMINER. 

pamphlet  No.  1727);  tell  how  it  is  inserted  to  make  a  tight  joint. 
Name  the  different  kinds  of  primers  used  in  the  battery.  Friction, 
electric,  combination  (electric-friction),  percussion,  igniting. 
Reload  a  drill  primer.  (Ordnance  Department  pamphlet  No. 
1881.) 

(d)  Cordage. 

How  is  the  size  of  a  rope  denoted  ?  How  do  you  serve  a  rope  ? 
Make  a  square  knot;  a  bowline;  rolling  hitch;  blackwall  hitch; 
round  turn  and  two  half  hitches;  clove  hitch.  What  is  a  strap 
or  sling,  and  what  is  its  use?  Make  a  shear  lashing.  Mouse  a 
hook  and  explain  for  what  purpose  used. 

Point  out  the  shell,  sheave,  pin,  strap  of  a  block,  and 
describe  the  different  kinds  (single,  double,  treble,  snatch,  and 
tail  blocks).  Point  out  the  running  part;  the  standing  part;  the 
fall  of  a  tackle. 

Rig  the  following:  Whip,  gun  tackle,  luff,  single  burton. 

Gins. — Name  the  different  parts  of  a  garrison-gin.  Explain 
briefly  how  it  is  assembled  and  raised  (the  drill  is  not  required). 
How  can  the  upper  block  be  placed  in  position  after  the  gin  has 
been  raised  ? 

Sheares. — What  do  sheares  consist  of,  how  are  they  rigged 
and  raised,  and  what  are  they  used  for?  How  and  when  is  the 
tackle  made  fast?  How  are  sheares  held  in  position  after  being 
raised  ? 

Hydraulic  Jacks. — For  what  is  a  hydraulic  jack  used  ?  What 
liquids  are  used  in  the  jack  ?  How  is  it  filled  and  emptied  ?  How 
is  the  jack  cared  for  when  not  in  use  ?  Show  how  to  use  the  jack 
when  lifting  a  heavy  weight;  in  lowering  a  heavy  weight;  use  of 
the  claw  in  connection  with  the  jack. 

(e)  U.  S.  Magazine  Rifle. — Nomenclature  of  the  piece,  kind 
and  weight  of  powder  used,  description  and  weight  of  projectile, 
muzzle  velocity.     Setting  of  sight  for  range  and  deflection. 


EXAMINATION  OF  CANDIDATES  FOR   GUNNERS.  7 

FIRST-CLASS   GUNNERS. 

(a)  Azimuth  Instrument  (pattern  in  use  by  the  company  for 
instruction),  definition  of  angles,  horizontal  angles,  verticle  angle, 
angle    measured    by    the    instrument,    leveling    and    orientation; 
focussing  the  telescope.     Graduation  of  the  instrument:     Set  up 
the  instrument  over  a  given  point  and  orient  it  from  sufficient 
data;    direct  the  telescope  successively  on  a  series  of  points  and 
read  their  azimuths  with  accuracy. 

(b)  The  Plotting-room  (for  guns). 

1.  Plolling-board. — Point    out  the    following:     Primary    and 
secondary  stations,  directing  gun,  displacement,  gun-arm,  travel- 
scale,     azimuth-correction     scale,  tally    dials,    range-correction 
scale. 

Lay  off  a  distance  of  so  many  yards  on  the  board;  conversely, 
tell  the  distance  in  yards  between  two  given  points  on  the 
board. 

The  azimuths  of  a  fixed  target  from  the  primary  and  secondary 
station  being  given,  locate  the  corresponding  point  on  the  board, 
and  give  its  azimuths  and  range,  fronxthe  directing  gun  or  direct- 
ing point. 

The  azimuths  of  a  fixed  target  from  the  primary  and  secondary 
stations  being  given,  locate  the  corresponding  point  on  the  board 
and  determine  its  range  and  azimuth  from  the  directing  gun  or 
point. 

2.  Range  Board. — Show  how  to  make  the  range  corrections 
for  atmosphere,  wind,  tide,  muzzle  velocity,  travel,  and  how  this 
range  correction  is  applied  to  the  range-correction  scale. 

3.  Deflection  Board. — Show  how  to  make  deflection  correction 
for  wind,  drift,  and  travel.     Show  how  to  make  azimuth  correc- 
tion in  Case  3  for  wind,  drift,  travel,  and  how  this  correction  is 
applied  to  azimuth  correction  scale. 

What  data  are  sent  to  the  guns  in  Case  i,  Case  2,  and 
Case  3  ? 

The  plotting-room  (for  mortars). 


8  THE  GUNNER'S  EXAMINER. 

1.  Plotting-board. — Point    out    the    following:     Primary    and 
secondary  stations,  directing  point,  gun-arm,  gun-arm  azimuth 
circle,  displacement,  powder  zones,  elevation,  times  of  flight. 

Lay  off  a  distance  of  so  many  yards  on  the  board;  conversely 
tell  the  distance  between  two  given  points  on  the  board. 

The  range  and  azimuth  of  a  fixed  point  (from  primary  station) 
being  given,  locate  the  corresponding  point  on  the  board.  Tell 
the  zone,  elevation  for  firing  at  this  point,  and  its  azimuth  from 
the  directing  point.  The  azimuth  of  a  fixed  target  from  the 
primary  and  secondary  stations  being  given,  locate  the  corre- 
sponding point  on  the  board  and  determine  its  range  and  azimuth 
from  the  directing  point. 

2.  Show  how  a  target  is  tracked,  how  to  get  travel,  how  the  time 
of  flight  is  used,  how  to   get  predicted  point,  how   to  get   set- 
forward  point.     What  is  the  predicted  point  used  for?    What  is 
the  set-forward  point  used  for?    What  data  are  sent  to  the  pit 
and  what  to  the  B.  C.  station?     Show  how  range  corrections  are 
made. 

3.  Drift  Device  (for  deflection  board  if  issued). — Show  how 
to  make  arbitrary  and  drift  corrections. 

(c)  Aiming  and  Laying  Guns  or  Mortars. 

1.  For  Rapid-fire  Guns. — Set  and  read  the  sight  for  given 
elevations  and  deflections;    aim  the  gun  at  some  object;    show 
how  elevating  and  traversing  handwheels  are  used;    explain  the 
use  of  the  deflection  scale  for  firing  right  arid  firing  left.     What 
is  Case  i  ? 

2.  For  Mortars. — Use  of  the  gunner's  quadrant,  setting  and 
reading  the  instrument,  when  and  how  placed  when  used  with 
mortars.     With   the   data  received  from  the   plotting  room  lay 
the  piece.     What  is  Case  3  ? 

3.  For  Heavy  Guns. — (Heavy  guns  refer  to  8-inch,  zo-inch, 
and  i2-inch  rifles  and  other  guns  which  are  provided  with  a 
system  of  vertical  and  horizontal  position  finders.)     Name  the 
principal  parts  of  the  telescopic  sight  (one  used  for  instruction 
purposes);   show  how  it  is  used.     Its  readings  for  elevation  and 


EXAMINATION   OF  CANDIDATES  FOR  GUNNERS.  9 

deflection,  east  count  of  its  scales.  Place  it  on  the  Hagood 
tripod  mount,  level  it;  set  it  for  given  elevation  and  deflec- 
tion. 

4.  Use  of  Difference  Chart. — An  example  like  the  following 
will  be  given:  Range  4500  yards,  azimuth  210.  Put  down  the 
corrected  range  and  azimuth. 

Examination  in  the  foregoing  subject  (c)  to  be  confined  to 
the  authorized  systems  in  use  by  the  company  during  the  year 
and  to  the  complete  equipment  of  the  battery  to  which  the  com- 
pany is  assigned. 

(d)  Elementary  Gunnery. — Axis  of  the  bore;  line  of  departure; 
line  of  sight;    drift;    muzzle  velocity;    quadrant  elevation;    sight 
elevation;    angle  of  fall;   jump;   trajectory;   time  of  flight. 

(e)  General  Features  of  Warships. — General  features  of  battle- 
ships (broad  beam  compared  to  length,  low  freeboard,  general 
massive  appearance,  large  turrets  fore  and  aft,  heavy  guns,  heavy 
armor,  generally  moderate  speed). 

Armored  cruisers:  (High  freeboard,  narrow  beam  compared 
to  length,  medium  armor,  medium  turrets,  medium  guns,  high 
speed) . 

Protected  cruisers:  (Fine  lines,  moderate  size,  no  armor, 
medium  guns  usually  with  shields,  protective  deck). 

Torpedo-boat  destroyers:  (High  bow,  generally  great  speed, 
light  guns,  no  armor). 

Torpedo  boats:   (Small  size,  high  speed,  no  armor). 

The  following  head  will  take  the  place  of  subject  (&)  in  the 
examination  of  candidates  for  first-class  gunners  of  organizations 
assigned  exclusively  to  rapid-fire  guns: 

(b)  Subcaliber  Firing. — The  15 -pounder  gun  and  subcaliber 
attachment  will  be  used.  The  target  will  be  Target  X,  miniature 
target,  page  25,  Small-arms  Firing  Regulations,  1906,  pasted 
on  a  screen  of  sufficient  size  to  catch  all  the  shots,  preferably 
the  screen  used  for  small-arms  Target  A;  range  about  95  feet, 
where  six  minutes  on  the  scale  is  equal  to  2  inches  at  the  target; 
method  of  scoring  as  prescribed  for  small-arms  practice. 


io  THE  GUNNER'S  EXAMINER. 

During  the  test  one  member  of  the  board  will  be  at  the  target 
and  will  personally  superintend  the  marking. 

The  preliminary  shots  will  be  fired  under  direction  of  the  ex- 
amining board  until  three  hits  have  been  obtained  with  the  same 
elevation  and  deflection.  The  center  of  impact  of  these  three 
shots  will  be  referred  to  the  horizontal  and  vertical  axes  through 
the  bulls' -eye  of  the  target  and  its  coordinates  carefully  measured. 
This  center  of  impact  will  not  be  on  the  miniature  target  and 
may  be  changed  by  the  board  as  often  as  they  deem  necessary 
during  the  examination.  These  measurements,  with  the  ele- 
vation and  deflection  used,  will  be  given  to  the  candidate,  who 
will  be  required  to  make  corrections  corresponding  to  the  dis- 
tance of  the  center  of  impact  from  the  bull's-eye.  Each  can- 
didate will  fire  five  shots,  the  piece  being  thrown  off  the  target 
between  shots.  Each  shot  will  be  marked  as  fired,  the  candidate 
making  such  changes  in  elevation  and  deflection  as  he  may  deem 
necessary  before  firing  the  next  shot.  The  ratio  of  the  candidates' 
score  to  the  maximum  score  possible  will  determine  the  credit, 
the  maximum  credit  being  20. 

After  this  test  the  candidate  will  fire  at  the  fixed  subcaliber 
target  anchored  at  about  500  yards,  without  knowing  the  exact 
distance,  five  rounds  under  service  conditions  in  one  minute  and 
thirty  seconds.  Three  sighting  shots  will  be  allowed  each  can- 
didate preceding  the  latter  test.  Each  hit  on  the  material  target 
counts  6. 

SYLLABUS  OF  EXAMINATION  FOR  CANDIDATES  FOR  GUNNERS  IN 

COMPANIES  AND  DETACHMENTS  ASSIGNED  TO  MINE 

DEFENSE. 

The  following  syllabus  gives  the  outline  of  the  scope  of  the 
et\amination  of  candidates  for  gunner  in  companies  and  detach- 
ments assigned  to  mine  defense.  It  is  not  intended  that  the 
theoretical  instruction  in  any  subject  shall  be  limited  to  what  is 
indicated  in  this  syllabus,  but  the  examination  for  candidates  for 
gunners  will  be  closely  confined  thereto. 


EXAMINATION  OF  CANDIDATES  FOR   GUNNERS.  II 


SECOND-CLASS   GUNNERS. 

(a)  Ammunition ,  Nomenclature,  and  Service  of  Guns  assigned 
to  the  Company  of  which  the  Candidate  is  a  Member. 

Duties  of  the  cannoneer  and  nomenclature  of  the  piece  to 
which  assigned.  (Note:  If  not  assigned  to  a  piece,  or  if  the 
company  is  assigned  to  different  pieces  of  different  calibers,  the 
candidate  will  be  examined  upon  the  piece  of  the  caliber  selected 
by  the  company  commander.) 

Describe  the  ammunition  and  name  all  the  projectiles  used 
for  the  piece  upon  which  examined. 

(b)  Material  of  and  Duties  in  the  Loading  Room  (except  elec- 
trical principles  involved}. 

What  apparatus  is  used  in  making  a  Turk's  head?  A  tele- 
graph joint?  A  joint  to  be  used  under  water?  Name  all  the 
parts  of  an  assembled  mine.  Name  all  the  parts  of  a  compound 
plug  and  explain  how  to  load  one.  What  is  a  cut-out  plug? 
Explain  how  to  prepare  a  cut-out  plug  and  box.  What  apparatus 
is  used  in  preparing  a  compound  plug?  How  are  mines  num- 
bered? How  are  mooring  pipes  prepared,  and  what  are  the 
rules  for  lengths  of  mine  cables  and  of  mooring  ropes? 

(c)  Material  for  and  Duties  on  the  Water. 

What  apparatus  is  taken  out  in  the  grand- junction  box-boat  ? 
How  and  in  what  way  are  the  cores  of  cable  numbered?  How 
is  a  mine,  together  with  its  attachments,  arranged  on  a  boat  for 
planting?  Name  the  apparatus  on  the  boat  used  in  planting 
and  raising  mines.  What  are  the  duties  in  the  triple- junction 
box-boat  in  planting  and  in  raising  mines,  and  what  precaution 
is  taken  so  that  cables  may  be  distinguished  when  box  is  raised? 
Explain  how  soundings  for  a  triple  group  are  made. 

(d)  Cordage. 

Name  the  important  knots  used  in  mine  work  and  explain 
how  to  make  four  of  them.  The  mooring  rope  of  a  heavy  weight 
cannot  pass  over  the  winch,  but  lifting  must  be  done  with  the 
fall;  explain  the  method  of  proceeding. 


12  THE  GUNNER'S  EXAMINER. 

(e)  U.  S.  Magazine  Rifle. — Nomenclature  of  the  piece,  kind 
and  weight  of  powder  used,  description  and  weight  of  projectile, 
muzzle  velocity.  Setting  of  sight  for  range  and  deflection. 

FIRST-CLASS   GUNNERS. 

(a)  Care  and  Preservation  of  Mine  Material. 

Name  the  supplies  necessary  for  cleaning  mine  material. 
Name  those  used  in  preserving  it,  stating  for  what  each  is  used, 
and  how  certain  ones  (to  be  selected  by  the  examiner)  are  applied. 

(b)  Handling  High  Explosives. 

What  high  explosives  are  used  in  mines?  What  are  the 
important  precautions  to  be  taken  in  loading  mines?  How  is 
frozen  dynamite  thawed  ?  Where  is  the  main  supply  of  explosive 
kept,  and  how  much  is  taken  out  at  one  time  to  the  explosive 
house  near  the  loading-room? 

(c)  Knowledge  and  Use  of  Azimuth  Instrument  and  Plotting 
Board. 

Names  of  important  parts.  Set  up  the  instrument  with  given 
data.  Read  angles  from  instrument.  Act  as  observer.  Act  as 
reader. 

Describe  a  plotting  board.  Explain  the  method  of  computing 
the  time  from  any  plotted  point  to  a  mine.  Act  as  plotter. 

(d)  Batteries,    Generators,    and   Searchlights   assigned    to    the 
Company  of  which  the  Candidate  is  a  Member. 

Name  the  batteries  used  in  mine  work.  Describe  the  case- 
mate battery.  What  precautions  are  necessary  in  keeping  it  in 
order?  What  is  used  as  the  signal  battery  in  mine  work?  De- 
scribe a  searchlight.  Describe  parts  of  generators  and  important 
points  to  be  observed  in  caring  for  them. 

(e)  Apparatus  and  Operation  of  Casemate  Switchboard  and 
Care  and  Use  of  Telephone. 

Name  the  apparatus  of  the  switchboard.  Explain  how  to 
fire  a  mine  by  judgment,  and  how  to  start  the  motor  generator. 
Explain  how  to  test  mine  and  cable  ends.  How  are  boat  tele- 


EXAMINATION  OF  CANDIDATES  FOR   GUNNERS  13 

phones  operated?  Name  the  parts  of  fire-control  telephones 
used  in  mine-commander  stations,  and  give  the  principal  points 
to  be  observed  in  operating  them. 

SECOND-CLASS   GUNNERS. 

General  Information. 

1.  Gunnery  is  the  science  and  art  of  operating  and  firing  guns. 

2.  A  gun  is  a  machine  which  throws  projectiles  with  great 
force  in  a  certain  direction  under  the  expanding  force  of  powder 
gas. 

3.  The  army  is  composed  of  the  following  divisions:  The  line 
and    the    staff.     The    line    is   composed    of   Infantry,    Cavalry, 
Artillery,  Engineers,  etc.     The  staff  of  Quartermaster  Dept.,  Com- 
missary Dept.,  Ordnance  Dept.,  Signal  Corps,  Pay  Dept.,  etc. 

4.  The  artillery  in  our  army  is  organized  as  a  corps  of  Coast 
Artillery  composed  of   169  companies  and  6  regiments  in  the 
Field  Artillery. 

5.  A  battery  of  coast   artillery  consists  of  two  or  more  guns 
or  two  or  more  pits  of  mortars. 

6.  A  fire  command  is  composed  of  two  batteries  or  more  whose 
fire  sweeps  the  same  area  or  adjoining  areas;  this  fire  is  controlled 
by  one  man,  called  the  fire  commander. 

7.  A  battle  command  is  two  or  more  fire  or  mine  commands 
sweeping  the  same  or  adjacent  areas;    this  commanded  by  one 
man — the  battle  commander. 

8.  A  mine  command  is  a  portion  of  submarine  defenses  and 
rapid-fire  guns,  all  commanded  by  one  man — the  mine  commander. 

9.  The  number  of  men  required  for  a  fire,  battle,  or  mine 
command  depends  on  the  number  and  caliber  of  the  guns  or 
mortars  or  the  size  of  the  mine  command. 

10.  The  number  of  men  in  a  coast  artillery  company  is  109; 
in  a  troop  of  cavalry  65,  in  a  company  of  infantry  60. 


THE   GUNNER'S   EXAMINER. 


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EXAMINATION  OF  CANDIDATES  FOR   GUNNERS.  15 

i2-inch  Mortars. — The  number  of  zones,  muzzle  velocities 
corresponding  thereto,  zone  limits,  width  of  zones  and  overlaps 
for  the  i2-inch  mortar,  cast-iron,  steel-hooped,  and  the  1 2-inch 
mortar,  steel,  have  been  rearranged  and  are  now  as  shown  by  the 
following  table : 


• 

*o 

1 

G 

3 
£ 

4 
6 

8 

12-inch  Mortar,  Cast-iron,  Steel- 
hooped. 

12-inch  Mortar,  Steel. 

JS 

F.  S. 
560 
610 
670 
743 
837 
910 
1050 

Weight  of 
Projectile. 

Zone  Limits. 

jl 

Overlaps. 

i 
9<~* 

Weight  of 
Projectile. 

H 

1 

"3  . 

jr 

Overlaps 

Lbs. 
1046 
1046 
1046 
1046 
1046 
1046 
824 

Yds. 
2225-3000 
2600-3480 
3080-4110 
3710-5000 
4600-6240 
5840-7319 

Yds. 

775 
880 
1030 
1290 
1640 
1479 

Yds. 
400 
480 
400 
400 
400 
594 

F.  S. 

55° 
600 
660 

725 
810 

1050 
1300 

Lbs. 
1046 
1046 
1046 
1046 
1046 
1046 
1046 
824 

Yds. 
2210—2970 
2600-3431 
3070-4030 
3631-4800 
4429-5940 
5520-7476 
7027-9250 

Yds. 
760 

831 

960 
1169 
1511 

1956 

2223 

Yds. 
37° 

399 
371 
420 

449 
492 

NOTE. — Each  smokeless -powder  cartridge  to  have  lo-ounce  igniter  (black  rifle  powder) 
at  each  end  in  addition  to  above  charges. 

All  smokeless-powder  charges  for  mortars  will  be  issued  made  up,  ready  for  use,  as 
the  charges  vary  with  each  lot  of  powder.  They  will  be  distinctly  marked  to  indicate 
the  zone  number. 


(a)    SERVICE  OF  THE  PIECE. 

Q.  Give  the  general  duties  of  a  gun  commander. 

A.  The  gun  commander  repeats  the  commands  "Commence 
firing"  and  "Cease  firing,"  announces  the  kind  of  projectile 
to  be  used,  the  order  to  fire,  the  method  of  pointing,  and  in  re- 
stricted fire  the  number  of  shots  and  the  firing  interval,  all  in 
accordance  with  the  orders  of  a  battery  commander.  The  gun 
commander  is  responsible  to  the  battery  commander  for  the 
condition  of  the  material  and  the  efficiency  of  the  personnel  of 
his  command. 


!6  THE  GUNNER'S  EXAMINER. 

Q.  Give  the  general  duties  of  a  chief  of  detachment. 

A.  Each  chief  commands  his  own  subdivision  whenever  it 
acts  separately;  is  responsible  for  its  drill  efficiency  and  for  the 
condition  of  the  material  to  which  it  is  assigned.  He  will  espe- 
cially see  that  the  gas-check  seat  is  clean  and  kept  free  from 
injury;  that  the  projectile  is  rammed  fully  home;  that  the  cham- 
ber is  sponged  properly  after  each  firing;  that 'the  vent  is  prop- 
erly served;  that  the  cylinders  are  properly  filled  and  the  throt- 
tling-valve  properly  set  before  firing;  that  the  mushroom  head 
and  gas-check  are  properly  adjusted;  that  the  kind  of  projectile 
designated  by  the  battery  commander  is  used,  and  that  the  breech 
detail  observe  great  care  and  caution  in  sponging  out  and  wiping 
breech  mechanism  and  recess  free  from  powder  residue,  dirt, 
etc.,  after  each  round  fired. 

Q.  Describe  how  to  signal  elevate  or  depress. 

A.  Elevate:  Raise  either  hand  to  the  height  of  the  head, 
fingers  pointing  upward.  Depress:  Raise  either  hand  to  the 
height  of  the  head,  fingers  pointing  downward. 

Q.  Describe  how  you  would  signal  traverse  right  or  traverse  left. 

A.  Motion  with  either  hand,  fingers  pointing  in  the  required 
direction. 

Q.  Give  the  signals  for  the  following :  Clamp  or  Halt ;  Ready. 

A.  Clamp  or  Halt:  Raise  either  arm  to  a  horizontal  posi- 
tion, fingers  closed.  Ready:  Raise  either  arm  vertically  to  its 
full  extent,  fingers  extended. 

Q.  How  would  you  signal  stand  fast  with  the  whistle  at  a 
rapid-fire  gun  ? 

A.  One  blast  signifies  stand  fast,  the  pause  being  of  sufficient 
duration  to  enable  orders  to  be  correctly  given  and  received; 
to  resume  operations  the  command  "  Go  on!"  will  be  given. 
Other  signals  may  also  be  used. 


EXAMINATION  FOR  SECOND-CLASS   GUNNERS. 


12-INCH    B.    L.    R.    DISAPPEARING    CARRIAGE.       (CHAIN    HOIST    ON 

LEFT    SIDE.) 

Q.  What  composes  a  gun  section  ? 

A.  A  gun  commander,  a  gun  detachment,  an  ammunition 
detachment,  and  a  reserve. 

Q.  How  many  men  in  a  gun  detachment? 

A.  One  chief,  one  gunner,  one  range-keeper,  and  eighteen 
privates. 

Q.  Name  the  details  into  which  a  detachment  is  divided,  and 
give  posts  of  each. 

A. 

Details. 

Chief  of  detachment 
(sergeant). 

Gunner  (duly  quali- 
fied non-commis- 
sioned officer  or 
private). 

Range-keeper  (non- 
commissioned of- 
ficer or  private). 

Breech  detail  (Nos. 
i,  2,  and  3). 


Posts. 


Two  yards  in  rear  of  the  breech,  facing  it 
or  wherever  presence  is  necessary. 

Sighting-platform  or  wherever  presence  is 
necessary. 


Near  the   elevation-scale,  on  the  right  or 
left  of  the  carriage. 


Nos.  i  and  2  in  line  immediately  in  rear  of 
the  breech,  facing  it,  No.  i  on  the  right; 
No.  3  on  the  right  of  the  piece,  two  feet 
from  and  facing  it,  opposite  the  elevating- 
band. 

At  the  platform  rail  facing  the  carriage,  No. 
4  opposite  the  rammer,  four  feet  from  its 
head,  Nos.  13  and  14  four  paces  to  his 
right  and  left  respectively. 

Elevating  detail  At  the  elevating  hand-wheels,  facing  them, 
No.  5  on  the  right  of  the  carriage,  No.  6 
on  the  left. 

Traversing  detail  In  front  of  the  traversing-cranks,  facing 
from  the  parapet,  No.  7  on  the  right  of 
the  carriage,  No.  8  on  the  left. 


Rammer  detail 
(Nos.  4,  13,  and 
14). 


(Nos.   5   and  6). 


(Nos.  7  and  8). 


i8  THE  GUNNER'S  EXAMINER. 

Details.  Posts. 

Tripping  detail    At  the  tripping-levers,  facing  the  carriage, 

(Nos.  9  and  10).          No.  9  on  the  right  of  the  carriage,  No.  10 

on  the  left. 
Truck    detail    Near  the  hoist,  in  rear  of  a  loaded  truck, 

(Nos.  ii  and  12).        No.  n  on  the  right,  No.  12  on  the  left, 

both  facing  the  truck. 
Telautograph  detail    At  the  telautograph. 

(No.  15). 
Hoist   detail    (Nos.     At  the  delivery-table  and  facing  it. 

16,  17,  and  18). 

Q.  Name  the  equipments  or  implements  which  each  member 
procures  and  places  in  proper  position  at  the  command  "Posts!" 
on  first  arriving  at  the  gun. 

A.  Gunner:   Sight  and  difference-chart. 

Range-keeper:  Stop-watch  and  prediction-scale. 

No.  i :  Translating  roller  or  crank,  can  with  sponge  and  oil, 
and  a  silk  wiper. 

No.  2:  Loading-tray  and  a  silk  wiper. 

No.  3:  Primer-pouch,  bag  for  empty  primers,  scabbard  con- 
taining punch,  gimlet,  and  reamer,  and  a  lanyard. 

No.  4,  assisted  by  No.  13:  Rammer. 

No.  9:  Wrench,  funnel,  and  measure  with  oil. 

No.  10 :  Chamber-sponge  and  wrench. 

No.  1 1 :  Dummy-cartridge  extractor. 

No.  12:  Shot-trucks. 

No.  13:  Same  as  No.  4  (Rammer).     No.  13  assists  No.  4. 

Q.  State  in  brief  what  each  member  of  the  gun  detachment 
inspects  and  tests  at  the  command  " Examine  gun!" 

A.  Chief  inspects  gun  and  carriage  throughout. 

Gunner  inspects  and  tests  sight,  sight-standard,  azimuth 
subscale,  traversing-gear,  and  firing-key. 

Range-keeper  inspects  elevating  gear. 

No.  i  removes  breech-cover  and  inspects  breech  mechanism, 
and  assists  in  sponging  bore  when  necessary. 


EXAMINATION  FOR  SECOND-CLASS   GUNNERS.  19 

No.  2  examines  bore,  chamber,  gas-check  seat,  and  breech- 
recess,  cleans  them  when  necessary,  and  oils  breech-recess. 

No.  3  cleans  vent  and  primer-seat,  hangs  lanyard  on  elevat- 
ing-arm. 

No.  4  brings  sponges  and  assists  Nos.  i  and  2  when  neces- 
sary and  replaces  sponges. 

Nos.  5  and  6  test  elevating-gear  with  range-keeper. 

Nos.  7  and  8  test  traversing-gear  with  gunner. 

Nos.  9  and  10  examine  recoil-cylinders  to  see  that  they  are 
properly  rilled.  No.  9  does  the  filling  with  oil  when  necessary. 
Wrenches,  funnel,  and  measure  are  passed  back  and  replaced, 
filling-plugs  replaced,  and  Nos.  9  and  10  take  posts  two  paces 
on  right  and  left,  respectively,  of  No.  4. 

No.  ii  receives  and  disposes  of  muzzle-cover,  passes  up  and 
replaces  funnel  and  oil-measure  when  necessary,  then  takes  post 
near  No.  12  at  the  trucks. 

No.  1 2  removes  muzzle-cover,  examines  trucks. 

No.  13  inspects  and  tests  telautograph.  If  a  telephone  is 
used,  he  puts  on  head  receiver  and  wears  it  until  dis- 
missed. 

Q.  Explain  briefly  how  to  open  a  breech  mechanism,  Model 
1888. 

A.  Figure  i  shows  breech  in  normal  position — closed.  No.  2 
turns  rotating  crank-catch  90°  to  left  and  turns  rotating-crank 
in  the  direction  of  the  arrow  till  it  stops  (Fig.  2). 

No.  i  turns  translating-roller  to  left  till,  at  the  end,  the 
shock  releases  the  block  (Fig.  3),  then  swings  block  free  to  right 
of  gun  till  it  engages  securing-latch  (Fig.  4).  Mechanism  1895 
is  opened  by  No.  3  turning  crank  continuously  till  motion  stops, 
being  careful  that  crank  does  not  catch  safety-lanyard. 

Q.  Give  duties  of  each  member  of  the  detachment  at  the 
command  "Load!" 

A.  Chief  commands:  (i)  "With  shot!"  (shell  or  dummy  pro- 
jectile); (2)  "Load!" 

Gunner   gives  direction    to   piece  according    to   the   system 


20 


THE   GUNNER'S  EXAMINER. 


used,  and  either  fires  electrically  or  signals  to  No.   3  to   fire. 
(Except  in  Case  3.) 

a 


Rotating 
Crank  Gate 


Guide  Rails 


Translating 
Roller 


FIG.  i. 


Range-keeper  calls  off  range,  using  predicting-scale,  and  cor- 
rects same  for  gun  difference;  signals  or  calls  out  "Elevation-set!" 


EXAMINATION  FCR  SECOND-CLASS   GUNNERS. 


21 


No.  i  assists  in  opening  and  closing  breech.     Examines  for 
dirt,  etc.,  the  breech-block  and    gas-check.     Oils  same.     When 


FIG.  2. 


necessary,  assists  in  ramming.     Places  third  section  of  cartridge 
on  shot-tray. 

No.  2  assists  in  opening  and  closing  breech,  examines  for  dirt, 


22  THE   GUNNER'S  EXAMINER. 

etc.,  and  oils  gas-check  .seat  and  threads  of  breech-recess.  He 
commands:  (i)  "Home!";  (2)  "Ram!"  Observes  scale  on 
rammer,  places  second  section  of  cartridge  on  front  part  of  shot- 
tray,  pushes  fourth  section  into  chamber,  such  that  its  base  will 
almost  clear  the  gas-check  seat.  If  necessary,  inserts  loading- 
tray  and  sponges,  assisted  by  No.  10. 


FIG.  3. 

No.  3  inserts  a  primer.  At  command  "Trip!"  steps  to  rear 
and  slightly  to  right  of  piece.  Fires  at  gunner's  signal.  Coils 
lanyard.  Removes  old  primer  and  places  it  in  a  bag. 

No.  4  brings  up  rammer  and  places  it  against  base  of  pro- 
jectile, assisted  by  Nos.  9  and  13.  Assists  in  ramming  projectile 
and  sections  of  cartridge.  Replaces  rammer  on  its  support. 


EXAMINATION  FOR  SECOND-CLASS   GUNNERS. 


23 


Nos.  5  and  6  set  the  elevation-scale  for  given  range. 
Nos.  7  and  8  traverse,  at  the  command  of  the  gunner. 
Nos.  9  and  10  assist  in   ramming.      Trip   the   piece.     After 
firing  No.   10  brings  up  chamber-sponge. 


Pinion  (inside  of  breech  pfate) 


Gear  Ring  (inside  of  breech  plate) 
Rotating  Ring 


FIG.  4. 

Nos.  ii  and  12  bring  loaded  truck  and  place  it  in  position, 
adjusting  height  of  shot-tray  to  that  of  the  breech.  No.  n  steps 
to  right,  and  No.  12  to  left,  of  truck.  If  there  be  a  brake,  No.  12 
sets  it;  if  not,  No.  n  chocks  the  front  wheels.  No.  12  places  first 
section  of  cartridge  on  tray,  No.  n  the  fourth.  Both  remove 
truck  to  delivery-table  and  take  posts  at  a  loaded  truck. 


24  THE  GUNNER'S  EXAMINER. 

Nos.  13  and  14  assist  in  ramming  projectile  and  sections  of 
cartridge.  Assist  9  and  10  at  pinch-bars  when  piece  will  not  trip. 

No.  13  assists  No.  4  in  bringing  up  and  replacing  rammer. 

No.  15  calls  out  and  posts  ranges  and  deflections  or  azi- 
muths received. 

No.  1 6  notifies  chief  of  ammunition  detachment  kind  of  pro- 
jectile required,  also  when  to  start  and  stop  the  hoist. 

Nos.  1 6,  17,  and  18  load  the  trucks. 

Q.  Give  the  positions  of  the  ramming  detail. 

A.  Nos.  i,  4,  9,  and  13  on  right.  Nos.  2,  10,  and  14  on  left. 
All  face  rammer  and  grasp  it  with  both  hands. 

Q.  Explain  the  method  of  ramming. 

A.  Nos.  13  and  14  take  hold  near  the  end  of  the  rammer, 
rammer-head  being  on  base  of  projectile.  At  the  command 
"Ram!",  all  rush  forward,  carrying  projectile  to  its  seat  with  force. 
Nos.  i  and  2  quit  the  rammer  when  near  the  truck.  First  three 
sections  of  cartridge  are  rammed  without  command. 

Q.  Explain  how  to  unload  a  dummy  charge. 

A.  The  chief  commands  "Unload!"  Breech  is  opened  and 
truck  brought  up  as  for  loading.  No.  4  brings  up  extractor  and 
pulls  out  sections.  No.  i  puts  two  sections  on  right  of  truck, 
No.  2  puts  others  on  left. 

Nos.  i,  2,  3,  and  4  withdraw  projectile  to  truck.  Truck  is 
removed  and  extractor  replaced. 

Q.  Explain  how  to  retract  a  gun. 

A.  Chief  commands  (i)  "From  battery!",  (2)  "Heave!",  (3) 
"Hali!" 

At  the  first  command  Nos.  7  and  8  go  to  the  retraction-cranks. 
No.  7  operates  the  retaining-pawl  and  speed-crank  to  permit  the 
pulling  out  of  the  ropes.  Nos.  9  and  10  mount  on  the  gun-levers 
and  place  the  ends  of  the  ropes  on  the  hooks,  receiving  them  from 
Nos.  3  and  4,  who  mount  on  the  chassis  to  assist.  Nos.  i  and 
2  pull  out  the  ropes  and  pass  the  ends  to  Nos.  3  and  4.  No.  7 
takes  in  the  slack.  Nos.  7,  8,  9,  and  10  take  positions  at  the 
retraction-cranks,  and  at  the  second  command  turn  the  cranks. 


EXAMINATION  FOR  SECOND-CLASS   GUNNERS.  25 

Nos.  3,  4,  5,  and  6  relieve  Nos.  7,  8,  9,  and  10  when  directed 
by  the  chief  of  the  detachment.  Odd  numbers  work  on  the 
right  side  of  the  carriage,  even  numbers  on  the  left  side.  When 
the  gun  has  reached  the  loading  position  the  command  "Halt!" 
is  given.  As  the  command  "Cast  off!"  is  given  No.  7  lets  out 
enough  slack  to  enable  Nos.  i  and  2  to  take  the  rope-ends  off  the 
hooks. 

Q.  Where  electric  motors  are  provided,  who  operates  them? 

A.  The  gunner  the  traversing-controllers,  No.  5  the  elevat- 
ing and  retracting  controllers ;  No.  6  watches  the  circuit-breakers, 
and  when  broken  by  an  overload  he  closes  the  breaker. 

Q.  When  the  shot-hoist  is  on  the  right,  what  changes  in  the 
service  of  the  piece  are  made? 

A.  No.  4  in  ramming  takes  position  between  Nos.  2  and  10 
on  the  left  side.  Nos.  10  and  14  assist  No.  4  in  bringing  up  and 
replacing  the  rammer,  instead  of  Nos.  9  and  13.  No.  9  brings 
up  and  replaces  sponge  and  assists  in  sponging,  instead  of  No.  10. 

Q.  How  many  men  in  the  ammunition  detail? 

A.  One  chief  and  twelve  privates. 

Q.  Name  the  details  into  which  it  is  divided,  and  the  numbers 
composing  each. 

A.  Hoist  detail,  Nos.  i  and  2. 

Projectile  detail,  Nos.  3,  4,  5,  and  6. 

Cartridge  detail,  Nos.  7,  8,  9,  10,  n,  and  12. 

Q.  Give  the  duties  of  each  in  brief. 

A.  No.  i  operates  the  controller  and  starts  the  hoist  supplying 
the  delivery-table  with  ammunition. 

No.  2  repeats  name  of  projectile  announced,  rolls  same  with 
cartridge  to  hoist-carrier. 

Nos.  3  and  4  operate  a  trolley  and  differential  pulley. 

Nos.  5  and  6  operate  another  trolley  and  pulley. 

Nos.  7  and  8  uncase  cartridges. 

Nos.  9,  10,  u,  and  12  place  sections  on  receiving-table  in 
proper  order.  If  electrical  power  fails,  Nos.  i  and  2  operate 
hoist  by  hand-cranks. 


26  riib   GUNNER'S  EXAMINER. 

Note. — Since  the  drills  for  the  ic-inch  and  8-inch  disappearing 
guns  differ  from  the  drill  for  the  1 2-inch  in  so  few  minor  details, 
no  separate  questions  and  answers  in  these  cases  are  given.  In 
the  lo-inch  piece  the  following  differences  were  noted:  Nos.  13  and 
14  are  omitted  in  the  rammer  detail;  No.  4  in  procuring  imple- 
ments attends  to  the  rammer  alone;  in  loading,  No.  2  pushes  the 
second  section  of  cartridge  into  the  chamber  instead  of  the  fourth ; 
in  ramming,  the  positions  from  front  to  rear  are  Nos.  i  and  9 
on  right,  Nos.  2,  4,  and  10  on  left,  facing  rammer,  etc.  When 
hoist  is  on  right  side  No.  10  assists  No.  4  (No.  13  being  left  out). 

In  the  8-inch  piece  the  rammer  detail  consists  of  No.  4  (13  and 
14  omitted),  the  truck  detail  of  No.  n  (12  omitted),  and  the 
hoist  detail  of  Nos.  16  and  17  (No.  18  omitted).  The  duties  of 
the  numbers  omitted  in  these  details  are  performed  by  the  re- 
maining numbers  in  that  detail,  otherwise  the  drill  is  precisely 
the  same  as  for  the  1 2-inch  piece.  In  extracting  a  dummy  Nos. 
2  and  3  do  not  assist  in  withdrawing;  Nos.  i  and  4  do  this. 


12-INCH  B.    L.    R.    MOUNTED   ON   NON-DISAPPEARING    CARRIAGE 
WITH    CHAIN   HOIST. 

Q.  How  many  men  in  a  detachment  ? 

A.  One  chief,  one  gunner,  one  range-keeper,  and  nineteen 
privates. 

Q.  Name  the  details  into  which  a  gun  detachment  is  divided, 
and  give  posts  of  each. 

A. 

Name  of  Detail.  Posts. 

Chief  of  detachment  (sergeant).  Two  yards  in  rear  of  the  car- 
riage-platform, facing  it. 

Gunner    (duly    qualified    non-  Sighting-platform, 
commissioned  officer  or  pri- 
vate). 

Range-keeper       (non-commis-  On  the  left  of  the  carriage,  oppo- 

sioned  officer  or  private).  site  the  elevation-scale. 


EXAMINATION  FOR  SECOND-CLASS  GUNNERS. 


27 


Name  of  Detail. 

Breech    detail    (four    privates, 
Nos.  i,  2,  3,  and  4). 


Elevating  detail  (two  privates, 

Nos.  5  and  6). 


Traversing  detail  (two  privates, 
Nos.  7  and  8). 


Sponge  and  rammer  detail  (two 
privates,  Nos.  9  and  10). 

Shot-hoist  detail  (four  privates, 
Nos.  n,  12,  13,  and  14). 


Truck  detail  (two  privates* 
Nos.  15  and  16). 

Telautograph  detail  (one  pri- 
vate, No.  17). 

Hoist  detail  (two  privates,  Nos- 
18  and  19). 


Posts. 

Nos.  i  and  2  immediately  in 
rear  of  the  breech,  Nos.  3 
and  4  one  yard  in  rear  of 
Nos.  i  and  2,  all  facing  the 
breech,  odd  numbers  on  the 
right. 

At  the  elevating  hand-wheels, 
facing  them,  No.  5  on  the 
right  of  the  carriage,  No.  6 
on  the  left. 

At  the  traversing-cranks,  facing 
the  carriage,  No.  7  on  the 
right  of  the  carriage,  No.  8 
on  the  left. 

One  yard  in  rear  of  the  car- 
riage platform,  facing  it,  No. 
9  on  the  right. 

No.  ii  opposite  the  shot-hoist 
tackle,  facing  the  carriage, 
Nos.  12  and  13  in  rear  of  the 
windlass  crank-handle,  facing 
it,  No.  13  on  the  right,  No.  14 
in  front  of  the  windlass  crank- 
handle,  facing  it. 

Near  the  hoist,  in  rear  of  a 
loaded  truck,  No.  15  on  the 
right. 

At  the  telautograph. 

At  the  delivery-table  and  facing 
it. 


The  posts  of  the  gun  detachment  as  given  above  are  for  inspec- 
tion, and  preparatory  to  the  service  of  the  gun. 

The  chief  of  detachment  and  gunner  go  wherever  their  pres- 
ence is  necessary. 

Q.  Name  the  equipments  or  implements  which  each  member 
procures  and  places  in  proper  position  at  the  command  "Posts!" 


28  THE   GUNNER'S  EXAMINER. 

A.  Gunner:  Sight  and  difference-chart. 

Range-keeper:  Stop-watch  and  prediction-scale. 

No.  i :  Translating-roller  (or  crank),  can  of  oil  with  sponge, 
lanyard,  and  silk  wiper. 

No.  2:  Loading-tray,  primer-pouch,  etc. 

No.  5 :  Wrench,  funnel,  and  measure  of  oil. 

No.  6:  Wrench. 

No.  9 :  Rammer  and  prop. 

No.  10 :  Chamber-sponge. 

No.  ii :  Dummy -extractor. 

Nos.  15  and  16:  The  trucks. 

Q.  State  in  brief  what  each  member  inspects  and  tests  at  the 
command  "Examine  gun!" 

A.  Chief:  Gun  and  carriage  generally. 

Gunner:  Sights  and  sight-standard,  azimuth  subscale,  travers- 
ing-gear,  and  firing-key. 

Range-keeper:  Elevating-gear. 

No.  i :  Removes  breech-cover  and  inspects  breech  mechanism. 

No.  2:  Bore,  chamber,  gas-check  seat,  breech-recess,  vent, 
primer-seat. 

Nos.  3  and  4  assist  in  sponging  bore  if  on  No.  2's  inspection 
it  is  found  to  need  it. 

Nos.  5  and  6:  Recoil-cylinders. 

No.  9  passes  up  funnel,  measure,  etc.,  to  No.  5. 

Nos.  7  and  8 :  Traversing-gear  with  gunner. 

No.  10  passes  up  and  replaces  sponge  when  necessary. 

Nos.  ii  and  12:  Shot-hoist  tackle;   remove  muzzle-cover. 

Nos.  13  and  14:  Shot-hoist  gearing. 

Nos.  15  and  16:  Trucks. 

No.  1 7 :  Telautograph  or  telephone. 

Q.  Give  duties  of  each  member  of  the  detachment  at  the 
command  "Load!" 

A.  Chief  gives  commands  for  loading. 

Gunner  and  range-keeper  same  as  for  1 2-inch  disappearing. 

No.  i  assists  in  opening  and  closing  breech.     Examines  for 


EXAMINATION  FOR.  SECOND-CLASS   GUNNERS  29 

residue,  dirt,  etc.,  the  breech-block  and  gas-check,  and  oils  same 
if  necessary.  Inserts  first  and  third  sections  of  cartridge. 
Adjusts  lanyard.  Fires  at  command  of  gunner. 

No.  2  assists  in  opening  and  closing  breech.  Examines  gas- 
check  seat  and  breech-recess ;  oils  and  cleans  the  same  if  necessary. 
Inserts  loading-tray.  Swings  projectile  into  position  and  gives 
commands  for  ramming.  Observes  scale  on  rammer.  Inserts 
second  and  fourth  sections  of  cartridge,  seeing  that  the  last 
section  is  properly  seated.  Removes  loading-tray.  Breech  being 
closed,  inserts  a  primer.  After  firing  removes  primer  and  places 
it  in  bag.  Assisted  by  No.  4,  sponges  chamber. 

No.  3  receives  rammer  and  places  it  on  base  of  projectile. 
Assists  in  ramming  projectile  and  first  three  sections  of  cartridge. 
Passes  rammer  back  to  No.  9. 

No.  4  assists  in  ramming.  Receives  chamber-sponge  and 
assists  in  sponging.  Passes  sponge  back  to  No.  10. 

Nos.  5  and  6  elevate  and  depress  the  piece. 

Nos.  7  and  8  traverse  the  piece  at  the  gunner's  command, 
and  assist  in  depressing  the  piece  if  necessary. 

No.  8  closes  safety-switch  at  command  "Ready!" 

No.  9  passes  up  rammer  to  No.  3,  and  assists  in  ramming. 
Replaces  rammer. 

No.  10  passes  up  and  replaces  chamber-sponge.  Mounts 
carriage-platform  and  assists  in  ramming. 

No.  ii  hooks  tackle  to  shot-tray  and  commands  "Hoist!", 
mounting  the  steps  and  steadying  the  projectile  in  time  to  com- 
mand "Halt!"  When  the  projectile  is  at  height  of  breech  com- 
mands "Lower!",  and  guides  tray  to  truck-platform  and  unhooks 
it. 

Nos.  12  and  13  hoist  the  projectile.  Pass  sections  of  cartridge 
to  Nos.  i  and  2. 

No.  14  assists  in  hoisting,  and,  while  Nos»  12  and  13  pass  up 
sections,  lowers  shot- tray. 

Nos.  15  and  16  bring  up  and  return  trucks. 

No.  17  calls  out  data  received  and  posts  it. 


30  THE   GUNNER'S  EXAMINER. 

No.  1 8  notifies  chief  of  ammunition  detachment  when  to 
start  and  stop  hoist.  Repeats  to  him  kind  of  projectile  designated. 

Nos.  1 8  and  19  load  the  trucks. 

Q.  Give  positions  of  rammer  detail. 

A.  Nos.  i,  3,  and  9  on  right;  Nos.  2,  4,  and  10  on  left, 
facing  rammer. 

Note.  —  No.  2  commands  "Ram!",  and  by  about  three 
separate  rushes  the  projectile  is  rammed  home;  No.  2  giving 
"Home!",  "Ram!",  when  the  brass  scale  on  rammer  is  about  two 
feet  from  face  of  breech.  Nos.  3  and  4  withdraw  rammer. 

Q.  Explain  how  to  unload  a  dummy. 

A.  Chief  commands  "Unload!"  (gun  being  depressed  to  o° 
elevation). 

No.  10  passes  extractor  to  No.  4,  who  withdraws  cartridge. 

Shot-tray  being  in  position  at  the  breech  as  in  loading,  Nos.  i, 
2,  3,  and  4  withdraw  projectile  to  shot-tray.  It  is  lowered  and 
replaced  by  the  shot-hoist  detail.  Where  no  chain  ammunition- 
hoist  is  provided  the  drill  will  be  modified  to  meet  the  conditions 
by  the  battery  commander. 

The  ammunition  detachment  and  duties  of  members  operating 
electric  motors  are  the  same  as  in  the  1 2-inch  disappearing-gun 
drill. 

Q.  In  what  particulars  does  the  drill  for  the  lo-inch  non- 
disappearing  gun  differ  from  the  12 -inch  non-disappearing? 

A.  First.  Nos.  i,  2,  3,  and  4  man  the  rammer. 

Second.  Sponge  and  rammer  detail  is  composed  of  No.  9 

only. 

Third.  Truck  detail  consists  of  No.  10  only. 
Fourth.  The  cartridge  detail  consists  of  four  men  only. 

DRILL    FOR   8-INCH   NON-DISAPPEARING. 

Q.  How  many  privates  in  a  detachment? 
A.  Fifteen. 

Q.  Name  the  details  into  which  a  detachment  is  divided,  and 
give  posts  of  each. 


EXAMINATION  FOR  SECOND-CLASS   GUNNERS. 


A. 

Name  of  Detail. 

Chief  of  detachment  (sergeant). 

Gunner  (duly  qualified  non- 
commissioned officer  or  pri- 
vate). 

Range  -  keeper  (non  -  commis- 
sioned officer  or  private). 

Breech  detail  (two  privates, 
Nos.  i  and  2). 

Elevating  detail  (two  privates, 
Nos.  3  and  4). 


Traversing  detail  (two  privates, 

Nos.  5  and  6). 


Shot-hoist  detail  (four  privates, 
Nos.  7,  8,  9,  and  10). 


Sponge  and  rammer  detail  (one 

private,  No.  n). 
Truck  detail  (one  private,  No. 

12). 

Tetlautograph  detail  (one  pri- 
vate, No.  13). 

Hoist  detail  (two  privates,  Nos. 
14  and  15). 


Posts. 

Two  yards  in  rear  of  the  car- 
riage, facing  it. 
Sighting-platform. 


On  the  left  of  the  carriage, 
opposite  the  elevation-scale. 

In  line,  immediately  in  rear  of 
the  breech,  facing  it,  No.  i 
on  the  right. 

At  the  elevating  hand-wheels, 
facing  them,  No.  3  on  the 
right  of  the  carriage,  No.  4 
on  the  left. 

In  front  of  the  traversing  cranks, 
facing  from  the  parapet,  No. 
5  on  the  right  of  the  carriage, 
No.  6  on  the  left. 

Nos.  7  and  8  at  the  windlass- 
cranks,  facing  to  the  rear,  No. 
7  on  the  right  of  the  carriage, 
No.  8  on  the  left,  No.  9 
opposite  the  shot-hoist  tackle, 
facing  the  carriage,  No.  10 
at  the  foot  of  the  steps  to  the 
carriage-platform,  on  the  left 
of  the  carriage,  facing  it. 

One  yard  in  rear  of  the  carriage- 
platform,  facing  it. 

Near  the  hoist,  in  rear  of  a 
loaded  truck. 

At  the  telautograph. 

At  the  delivery-table,  facing  it. 


32  THE  GUNNER'S  EXAMINER. 

The  posts  of  the  gun  detachment  as  given  above  are  for  inspec- 
tion, and  preparatory  to  the  service  of  the  gun. 

The  chief  of  detachment  and  gunner  go  wherever  their  pres- 
ence is' necessary. 

Q.  Name  the  equipments  or  implements  which  each  member 
procures  and  places  in  proper  position  at  the  command  " Posts!" 

A.  Gunner,  range-keeper,  Nos.  i,  2,  5,  and  6  procure  the 
same  as  for  the  1 2-inch  piece. 

No.  9:  Chamber-sponge. 

No.  10:  Extractor  for  dummy. 

No.  1 1 :  Rammer  and  prop. 

No.  12:  Trucks. 

Q.  State  in  brief  what  each  member  inspects  and  tests  at  the 
command  "Examine  gun!" 

A.  Chief,  gunner,  range-keeper,  Nos.  i  and  2  the  same  as 
for  the  i2-inch  piece,  Nos.  3  and  4  the  elevating -gear. 

Nos.   5   and  6:  Recoil-cylinders,   traversing  gear. 

No.  7  passes  up  and  replaces  funnel  and  measure. 

No.  8:  Hoisting-gear,  and  removes  muzzle-cover. 

No.  9  and  10:  Tackle  of  shot-hoist. 

No.  ii  passes  up  and  replaces  sponges. 

No.  12:  Trucks. 

No.  13:  Telautograph  or  telephone. 

Q.  Give  the  duties  of  each  at  the  command  "Load!" 

A.  Chief,  gunner,  and  range-keeper  are  the  same  as  for  the 
12-inch  piece. 

No.  i  assists  in  opening  and  closing  breech.  Examines  gas- 
check  and  breech-block.  Assists  in  launching  projectile  on  the 
loading-tray.  Assists  in  ramming  projectile.  Passes  back  to 
No.  ii  the  rammer.  Hooks  lanyard  to  firing-leaf.  Fires  at 
signal  of  gunner. 

No.  2  assists  in  opening  and  closing  breech.  Examines  gas- 
check  seat  and  breech-recess.  Inserts  loading-tray.  Commands 
"Home!",  "Ram!",  and  assists  in  ramming.  Observes  scale  on 
rammer.  Inserts  sections  of  cartridge  and  pushes  them  home  by 


EXAMINATION  FOR  SECOND-CLASS   GUNNERS  33 

hand.  Removes  loading-tray.  Inserts  a  primer  and  lowers  slide. 
Removes  old  primer  and  places  it  in  a  bag.  Sponges  chamber. 

Nos.  3  and  4  elevate  the  piece. 

Nos.  5  and  6  traverse  the  piece. 

Nos.  7  and  8  hoist  the  projectile  at  the  command  "Hoist!" 
No.  8  lowers  the  shot-tray. 

No.  9  hooks  the  tackle  to  the  shot-tray  and  commands  "  Hoist  1" 
Steadies  the  projectile.  Places  section  of  cartridge  on  rear  of 
carriage-platform. 

No.  10  mounts  steps  and  commands  "  Halt !"  when  projectile 
is  level  with  breech.  Launches  it  on  loading-tray,  and  swings 
shot-tray  clear  of  carriage-platform  and  resumes  post. 

No.   ii  passes  rammer  to  No.  2. 

As  soon  as  projectile  is  rammed  passes  both  sections  of  car- 
tridge to  No.  2  and  returns  rammer. 

No.  12  brings  up  and  returns  trucks.  . 

No.  13  calls  out  and  posts  data  received. 

No.  14  repeats  to  ammunition-sergeant  kind  of  projectile  to  be 
used;  also  notifies  when  to  start  and  stop  the  hoist. 

Nos.  14  and  15  load  the  trucks. 

Q.  How  is  a  dummy  charge  unloaded? 

A.  The  gun  is  brought  to  o°  elevation.  No.  11  passes  up 
extractor.  No.  2  withdraws  sections  of  cartridge.  No.  10  passes 
them  to  No.  n,  who  places  them  on  truck.  The  shot-tray  is 
held  in  position  while  No.  2  withdraws  the  projectile  to  the 
shot-tray,  when  it  is  lowered  to  the  truck. 

Note. — The  ammunition  detachment  is  the  same  as  prescribed 
for  the  12-inch  disappearing  gun. 

1 2 -INCH  MORTAR,  MODEL  1896. 

Q.  What  comprises  a  gun  detachment? 
A.  Chief  of  detachment,  gunner,  and  ten  privates. 
Q.  Name  the  details  into  which  it  is  divided,  and  give  the 
posts  of  each. 


34 


THE   GUNNER'S  EXAMINER. 


A. 

Name  of  Detail. 

Chief  of  detachment  (sergeant). 

Gunner  (duly  qualified  corporal 

or  private). 
Breech    detail    (two    privates, 

Nos.  i  and  2). 

Sponge  and  rammer  detail  (two 
privates,  Nos.  3  and  4). 

Elevating  detail  (two  privates, 
Nos.  5  and  6). 


Traversing  detail  (two  privates, 

Nos.  7  and  8). 

Truck    detail     (two    privates, 
Nos.  9  and  10). 


Posts. 

Two  yards  in  rear  of  the  breech, 

facing  it. 
Near    the     azimuth    subscale 

facing  the  mortar. 
In  line  immediately  in  rear  of 

the  breech,  facing  it,  No.   i 

on  the  right. 
At    the    sponge    and    rammer, 

facing  the  mortar. 
At  the  elevating  hand-wheels, 

facing  them,   No.   5   on  the 

right  of  the  carriage,  No.  6 

on  the  left. 
At  the  traversing-cranks,  facing 

the  mortar,  No.  7  at  the  right 

crank,  No.  8  at  the  left. 
In  the  gallery,  near  the  entrance, 

in  rear  of  and  facing  a  loaded 

truck,  No.  9  on  the  right,  No. 

10  on  the  left. 


The  posts  of  the  gun  detachment  as  given  above  are  for  in- 
spection and  preparatory  to  the  service  of  the  mortar. 

Q.  State  in  brief  what  equipments  or  implements  each  pro- 
cures and  places  in  proper  positions. 

A.  No.  i:  Oil-can,  hand-sponge,  and  silk  wiper. 

No.  2 :  Silk  wiper. 

No.  3 :  Long  lanyard,  bore  and  chamber  sponge. 

No.  4:  Rammer. 

No.  5 :  Wrench  for  filling  plug. 

No.  6:  Wrench  for  filling  plug,  measure  and  funnel. 

No.  8:  Primer- pouch,  bag,  scabbard,  etc. 
Q.  How  is  a  breech-block  opened  and  closed? 
A.  In  the  same  manner  as  for  the  8-,  10-,  and  1 2-inch  guns. 
Q.  What  does  each  member  of  the  detachment  inspect  or 


EXAMINATION  H)R  SECOND-CLASS   GUNNERS.  35 

test  with  a  view  of  cleaning  or  oiling,  if  necessary,  at  the  command 
''Examine  gun!"? 

A.  Chief:  Mortar  in  general. 

Gunner:  Azimuth  subscale  and  traversing-gear. 

No.  i :  Breech-block  and  breech  mechanism. 

No.  2:  Bore,  chamber,  gas-check  seat,  and  breech-recess. 

No.  3:  Lanyard.     (He  coils  it  properly.) 

No.  4:  Muzzle-cover.     (Removes  it  and  places  it  aside.) 

Nos.  5  and  6 :  Elevating-gear  and  recoil-cylinders. 

Nos.  7  and  8:  Traversing-geac.  No.  8  clears  vent  and  wipes 
primer-seat. 

Nos.  9  and  10:  Trucks. 

Q.  After  examining  gun,  what  changes  in  posts  are  made  ? 

A.  The  chief  of  detachment  and  gunner  go  wherever  their 
presence  is  necessary.  No.  7  takes  post  at  the  door  of  the  car- 
tridge-room. 

Q.  Give  the  duties  of  each  member  of  the  detachment  at 
the  command  "Load!" 

A.  Gun  commander  operates  switches  and  firing-plug.  Ob- 
serves all  detachments. 

Chief  generally  supervises  the  proper  loading  of  his  piece, 
singals  "Ready"  or  "Misfire,"  etc. 

Gunner  gives  the  piece  the  proper  azimuth,  signals  "Azi- 
muth set"  to  the  chief. 

No.  i  assists  in  opening  and  closing  breech.  Examines  or 
oils,  if  necessary,  the  breech-block  and  gas-check.  Assists  in 
ramming 

No.  2  assists  in  opening  and  closing  breech.  Examines  or 
oils,  if  necessary,  the  gas-check  seat  and  breech- recess.  Com- 
mands "Home!",  "Ram!"  Assists  in  ramming.  Observes  the 
scale  on  the  rammer.  Inserts  loading-tray  and  withdraws  same. 
Pushes  cartridge  properly  into  chamber.  After  firing,  assisted 
by  No.  5,  sponges  chamber  and  bore. 

No.  3  assists  in  ramming.  If  firing  by  lanyard  be  used,  he 
attaches  the  long  lanyard  to  the  short  one  and,  after  the  piece  is 


36  THE  GUNNER'S  EXAMINER. 

elevated,  hooks  the  short  lanyard  to  eye  of  firing-leaf  and  fires  at 
the  command.  After  firing,  brings  bore  and  chamber-sponge  and 
assists  No.  2  in  sponging.  Replaces  sponge. 

No.  4  brings  up  rammer,  and  places  its  head  on  the  base  of 
the  projectile.  Assists  in  ramming.  Replaces  rammer. 

Nos.  5  and  6  give  elevation  at  command  of  chief.  (No.  5 
operates  the  clamp  and  lock.)  Assists  in  ramming. 

After  piece  is  fired,  brings  piece  to  o°  elevation. 

No.  7  brings  up  cartridge  and  takes  post  at  traverse-crank. 
On  taking  cover  he  returns  to  cartridge-room. 

No.  8  inserts  and  removes  primers. 

Nos.  7  and  8  traverse  the  mortar  at  the  signal  of  the  gunner. 

Nos.  9  and  10  bring  up  loaded  trucks. 

Q.  What  are  the  positions  for  ramming? 

A.  Nos.  i,  3,  and  5  on  right,  Nos.  2,  4,  and  6  on  left,  all  facing 
rammer.  The  projectile  is  rammed  home  in  one  motion. 

Q.  In  taking  cover,  what  is  the  order  of  formation  in  rear  of 
pits? 

A.  They  take  cover  as  shown  in  the  following  diagram: 

Mortar  No.  4  Mortar  No.  2 


i  t 


3 


C  8, 6,  5,  G. )  (  8,  6,  5,  G. ) 

4th  detachment  \  [    2d  detachment  ] 

l-4»3t*»z  '''  U,3i2|i     ) 

3d  detachment    j  8'  6'  5'  °'  }   ist  detachment  j  8'  6'  5'  °'  [ 
IjJ&M    J  <4,3>2>I     ) 

Q.  What  comprises  an  ammunition  detachment  ? 
A.  One  chief,  two  corporals,  and  sixteen  privates. 
Q.  Name  the  details. 
A.  Projectile:  One  corporal  and  Nos.  i  to  12. 

Cartridge:  One  corporal  and  Nos.  13  to  16. 
Q.  Give  their  duties  in  brief. 


EXAMINATION  FOR  SECOND-CLASS   GUNNERS.  37 

A.  The  chief  has  general  supervision  and  is  responsible  for  the 
proper  supply  of  ammunition. 

Nos.  i  and  2  operate  a  trolley  and  pulley,  and  load  trucks 
with  shell. 

Nos.  3  and  4,  5  and  6,  7  and  8  operate  other  trolleys  similarly. 

Nos.  9,  10,  n,  and  12  run  up  empty  trucks,  and  when  loaded 
return  them  to  gallery  entrance. 

Nos.  13,  14,  15,  and  16  pass  designated  cartridge  to  No.  7. 

Note. — Where  there  are  two  magazines  to  an  emplacement 
there  is  a  separate  detachment  for  each,  composed  of  three  non- 
commissioned officers  and  eight  privates  each.  (Nos.  i  to  6 
compose  the  projectile  detail,  and  Nos.  7  and  8  the  cartridge 
detail.) 

Q.  How  does  the  drill  for  the  1 2-inch  mortar  carriage,  model 
1891,  differ  from  that  of  model  1896? 

A.  Nos.  i  and  2  lift  shell-tray  from  hoist-scoop  to  truck  after 
ramming. 

Nos.  5  and  6  man  the  shell-hoist  and  hand-wheel,  in  addition 
to  assisting  in  ramming. 

No.  6  returns  to  hoist  hand-wheel  after  ramming,  and  lowers 
scoop  when  directed  by  No.  2. 

Nos.  9  and  10  deliver  shell  on  scoop,  and  return  truck. 

6-INCH    DISAPPEARING. 

Q.  What  composes  a  gun  detachment? 

A.  One  chief,  a  gunner,  and  ten  privates. 

Q.  What  are  their  posts  preparatory  to  inspection  or  service 
of  the  piece? 

A.  Chief  of  detachment,  two  yards  in  rear  of  the  breech, 
facing  it. 

Gunner,  sighting-platform. 

No.  i,  two  feet  to  the  right  and  rear  of  the  breech,  facing  it. 

No.  2,  two  feet  to  the  left  and  rear  of  the  breech,  facing  it. 

No.  3,  two  yards  in  rear  of  the  breech,  facing  it. 

No.  4,  at  the  elevating  hand-wheel,  facing  it. 


38  THE  GUNNER'S  EXAMINER. 

Nos.  5  and  6,  at  the  serving-table  at  the  rear  side  of  the 
loading-platform,  facing  to  the  front,  No.  5  on  the  right  side,  No.  6 
on  the  left. 

No.  7,  on  the  gun-platform  at  the  head  of  the  steps  leading 
to  the  cartridge-room. 

No.  8,  at  the  telautograph. 

Nos.  9  and  10,  on  the  banquette,  facing  the  gun,  No.  9  on 
the  right. 

Q.  What  implements  or  equipments  do  each  procure? 

A.  Gunner:  Sight  and  difference-chart. 

No.  i:  Silk  wiper,  lanyard,  sponge  and  oil-can. 

No.  2:  Loading-tray  and  silk  wiper. 

No.  3:  Rammer  and  prop. 

No.  5:  Plug-wrench,  funnel  and  measure. 

No.  6:  Plug-wrench. 

No.  7:  Chamber- sponge  and  dummy-extractor. 

Q.  What  does  each  inspect  or  test  with  a  view  to  cleaning  or 
oiling,  if  necessary,  at  the  command  "Examine  gun!"? 

A.  Chief:  Gun  and  carriage  throughout. 

Gunner:  Sight-standard,  sight,  azimuth  subscale,  traversing- 
and  elevating-gears. 

No.  i :  (Removes  breech-cover)  breech-block  and  breech  mech- 
anism, vent,  lanyard  (hangs  lanyard  on  elevating-arm). 

No.  2:  Bore,  chamber,  gas-check  seat,  and  breech  recess,  and 
cleans  them  if  necessary. 

No.  3:  The  sponges  (hangs  them  up  when  necessary). 

No.  4:  (Removes  muzzle-cover,  etc.)  elevating-  and  traversing- 
gears  under  gunner's  direction. 

Nos.  5  and  6:  Recoil-cylinders. 

No.  7  passes  up  funnel  and  oil-measure  when  used. 

No.  8:  Telautograph  or  telephone. 

Q.  Give  in  brief  the  duties  of  each  at  the  command  "Load!" 

A.  Those  of  chief  and  gunner  are  practically  the  same  as 
for  the  8-inch  disappearing. 

No.  i  opens  breech  (by  one  continuous  motion).      Inserts  a 


EXAMINATION  FOR  SECOND  CLASS   GUNNERS.  39 

primer  and  takes  lanyard.  Closes  breech.  Fires  at  the  signal. 
After  piece  is  fired  coils  lanyard,  and  opens  breech  and  removes 
primer. 

No.  2  inserts  loading-tray.     Inserts  cartridge  by  hand. 

No.  3  rams  projectile  home.  Replaces  rammer.  Operates 
tripping-lever,  and  trips  at  the  command.  After  piece  is  fired 
sponges  chamber. 

No.  4  sets  the  elevation,  signalling  "Elevation  set"  by  holding 
one  hand  at  height  of  head  until  signal  "Ready"  is  made  by 
chief. 

Nos.  5  and  6  alternate  in  bringing  up  projectiles  and  placing 
them  on  the  loading-tray. 

No.  7  receives  a  cartridge  from  No.  4  or  No.  5  of  the  ammu- 
nition detachment.  Passes  it  to  No.  2.  Closes  safety-switch 
when  gun  is  in  battery. 

No.  8  calls  out  and  posts  data  received. 

Nos.  9  and  10  receive  projectiles  from  a  truck  and  place 
them  on  serving-table. 

Q.  How  is  a  dummy  charge  unloaded? 

A.  The  chief  of  detachment  commands:  " Unload!" 

No.  i  opens  the  breech. 

No.  2  inserts  the  loading-tray,  withdraws  the  cartridge  and 
passes  it  to  No.  7,  and,  as  soon  as  the  projectile  is  withdrawn, 
removes  the  loading- tray. 

No.  3  brings  up  the  extractor,  pulls  the  projectile  on  to  the 
loading-tray,  and  replaces  the  extractor. 

No.  5  withdraws  the  projectile  and  returns  it  to  the  serving- 
table. 

No  7  carries  the  cartridge  to  the  steps  and  passes  it  to  No. 
4  or  No.  5  of  the  ammunition  detachment. 

Q.  How  is  the  piece  retracted? 

A.  The  chief  of  detachment  commands:  (i)  "From  battery !"; 
(2)  "Heave!  ";  (3)  "Halt!  "  At  the  first  command  No.  3  goes  to 
the  retraction-crank  and  operates  the  pawl  and  speed-crank  to 
permit  the  pulling  out  of  the  ropes.  Nos.  5  and  6  mount  on  the 


40  THE   GUNNER'S  EXAMINER. 

carriage  and  place  the  loops  of  the  ropes  on  the  hooks.  Nos.  i 
and  2  pull  out  the  ropes  and  pass  the  ends  to  Nos.  5  and  6. 
No.  3  takes  in  the  slack.  Nos.  3  and  4  take  positions  at  the 
retraction-crank,  and  at  the  second  command  turn  the  crank. 
Nos.  5  and  6  relieve  Nos.  3  and  4  when  directed  by  the  chief  of 
detachment.  When  the  gun  has  reached  the  loading  position 
the  command  "Halt!"  is  given.  At  the  command  "Cast  off!" 
No.  3  lets  out  enough  slack  to  enable  Nos.  i  and  2  to  take  the 
loops  off  the  hooks. 

Q.  In  an  emplacement  provided  with  an  ammunition -hoist 
what  changes  in  the  above  drill  are  made? 

A.  Nos.  5  and  6  serve  projectiles  from  a  loaded  truck  placed 
in  rear  of  the  gun. 

Nos.  9  and  10  are  posted  at  the  delivery-table,  and  run  loaded 
trucks  to  Nos.  5  and  6,  returning  empty  ones. 

Q.  What  composes  an  ammunition  detachment  ? 

A.  One  chief  and  five  privates.  Nos.  i,  2,  and  3  in  the  shell - 
room,  and  Nos.  4  and  5  in  the  cartridge-room. 

Q.  Give  their  duties  in  brief. 

A.  The  chief  exercises  general  supervision. 

Nos.  i  and  2  load  trucks. 

No.  3  runs  up  trucks  convenient  to  the  rear  of  gun,  and  returns 
them  to  shell-room. 

Nos.  4  and  5  uncase  cartridges  and  pass  them  to  No.  7. 

Note. — Owing  to  the  comparative  simplicity  and  the  simi- 
larity of  drill  of  almost  all  smaller-calibered  pieces  they  are  omitted 
in  this  work. 

For  definite  details  in  the  drill  for  6-inch  Pedestal,  5 -inch 
Balanced  Pillar,  4.7-inch  Quick-firing,  i5-pounder  and  6- 
pounder  Rapid-fire  Guns,  see  Coast  Artillery  Drill  Regulations. 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


NOMENCLATURE  AND  GENERAL  DESCRIPTION. 

Q.  What  are  projectiles  ? 

A.  They  correspond  to  the  bullets  in  small-arm  cartridges. 

Q.  Why  are  projectiles  made  oblong  and  guns  rifled? 

A.  To  prevent  the  projectile  from  tumbling,  thereby  securin ; 
greater  penetration,  and  better  results  in  accuracy  of  fire. 

Q.  What  is  the  difference  between  guns  and  mortars? 

A.  Guns  are  long  in  comparison  with  their  calibers,  mortars 
are  short  in  comparison  with  their  calibers. 

Q.  What  is  meant  by  a  built-up  gun  ? 

A.  One  that  is  composed  of  several  cylindrical  forgings  sepa- 
rately shrunk  one  over  the  other. 

Q.  Why  are  these  forgings  shrunk  on  ? 

A.  To  give  an  initial  compression  to  the  steel  toward  the  bore, 
such  that  the  strength  of  the  gun  to  resist  the  pressure  of  the 
powder-gas  will  be  increased. 

Q.  Name  the  principal  parts  of  a  built-up  gun. 

A.  The  tube,  jacket,  hoops,  and  trunnion-band.  (See  Figs. 
5,  6,  and  23.) 


Powder  Chamber 
Breech 


Copper  Packing  Ring          Forcing  Cone 


DIAGRAM  SHOWING  ARRANGEMENT  OF  FORGINGS. 
Bore     F.o.6    Key  Ring 


Screw  Bo 


Breech  Plate 

Powder  Chamber  Shot  Cham  be  r  •p111^^^     Trunnion  Band 

Rim  Base        Trunnion 
BUILT  UP  GUN.       FiG.5 

Q.  What  is  a  wire-wound  gun  ? 

A.  One  in  which  wire  takes  the  place  of  the  jacket  and  hoops 
and  is  wound  over  the  tube.  The  wire  is  really  in  the  form  of  a 
ribbon.  < 

Q.  Define  the  breech-reinforce. 


42  THE  GUNNER'S  EXAMINER. 

A.  That  portion  of  the  gun  between  the  rear  of  the  trunnion, 
band  and  the  front  of  the  breech.  (Fig.  5.) 

Q.  Define  the  chase. 

A.  That  portion  of  the  gun  between  the  front  of  the  trunnion- 
band  and  the  muzzle.  (Fig.  5.) 

Q.  What  is  a  barbette  gun  ? 

A.  One  that  fires  over  a  parapet. 

Q.  What  two  classes  of  barbette  guns  are  there? 

A.  Barbette  disappearing  and  barbette  non-disappearing. 

Q.  What  is  the  center  of  gravity  ? 

A.  That  point  where,  if  the  gun  were  pivoted,  it  would  bal- 
ance. It  is  always  near  the  trunnions. 

Q.  What  is  the  difference  between  front-pintle  and  center- 
pintle  carriages  ? 

A.  Front  pintle  is  where  the  gun  traverses  about  a  point  in 
the  front  part  of  the  carriage;  center  pintle  where  it  traverses  about 
a  point  in  the  center  of  the  carriage. 

Q.  What  is  a  rack? 

A.  A  bar  or  arc  having  teeth  that  engage  in  a  gear-wheel 
or  worm.  (See  Fig.  7.) 

Q.  What  is  a  gear-wheel  ? 

A.  A  wheel  with  teeth  on  the  circumference. 

Q.  What  is  a  bevel-gear  ? 

A.  Two  wheels  whose  axles  are  at  an  angle  to  each  other  and 
whose  teeth  engage.  (Fig.  8.) 

Q.  What  is  a  miter-gear  ? 

A.  A  bevel-gear  with  axles  of  equal-sized  wheels  at  right 
angles.  (Fig.  9.) 

Q.  What  is  a  worm  ? 

A.  A  gear-wheel  in  the  form  of  a  continuous  screw.     (Fig.  10.) 

Q.  What  is  a  sprocket-wheel  ? 

A.  A  toothed  wheel  that  engages  the  links  of  a  chain.     (Fig. 

n.) 

Q.  What  is  a  spur-wheel  ? 

A.  A  gear-wheel  with  teeth  parallel  with  the  axle  of  the 


NOMENCLATURE  AND   GENERAL  DESCRIPTION* 


43 


wheel.     If  in  Fig.  7  the  rack  were  in  form  of  a  wheel,  it  would 
be  a  spur-wheel.     (The  pinion  is  also  a  spur-wheel.) 


«IACK  AND  PINION. 
FIG.  7 


MITRE  GEAR. 
FIG.  9 


BEVEL  GEAR. 
FIG.  8 


WORM  GEAR.^ 
FIG.  10 


SPROCKET  WHEEL 

AND  CHAIN. 

FIG.  11 


Q.  Point  out  or  describe  the  location  of  the  following  parts 
of  a  seacoast  carriage: 


Base-ring. 

Foundation-bolts. 

Leveling-bolts. 

Upper-roller  path. 

Lower-roller  path. 

Traversing-rack. 

Conical  rollers. 

Distance-ring. 

Dust-guard. 

Racer. 

Chassis. 

Top-carriage. 

Recoil-cylinder. 

Piston. 

Piston-head. 

Throttling-bars. 


Followers. 
Stuffing-box. 
Packing. 
Guide-hooks. 
Trunnion-bed. 
Trunnions. 
Kim-base. 
Cap-squares.    . 
Cap-square  bolts. 
Elevating  mechanism. 
Traversing  mechanism. 
Azimuth  circle. 
Azimuth  indicator. 
Retraction-gear. 
Sight  standard. 
Shot-hoist. 


44 


THE   GUNNER'S  EXAMINER. 


Crane. 

Shot-hoist  drum. 

Pawl. 

Elevating-arc. 

Recoil-rollers. 
Extra  for  R.  F.  guns: 

Pillar-base. 

Shoulder-rest. 

Electric  batteries. 
Extra  for  disappearing  guns: 

Gun-lever. 

Lever-axle. 

Counterweight-shaft. 

Counterweight. 

Cross-head. 

Cross-head  guides. 

Cross-head  rack. 
A.   See  Figs.  12  to  22  inclusive. 


Chassis-rails. 
Gun-shield  support 
Loading-platform. 
Elevating-shaft. 


Pistol-grip. 
Range-drum. 


Tripping-bars. 
Counter-recoil-buffers. 
Gunner's  platform. 
Retraction-ropes. 
Extra  recoil-buffers. 
Electric  traversing-controller. 
Electric  elevating-controller. 


BREECH-BLOCKS,    RECOIL-CYLINDERS,    ETC. 

Q.  Point  out  or  describe  the  location  of  the  following  parts 
of  the  gun  and  breech  mechanism  of  8"  and  12",  Model  1888: 


Bore. 

Shot-chamber. 

Muzzle. 

Powder-chamber. 

Forcing-cone. 

Screw-box. 

Breech-block. 

Mushroom  head. 

Spindle. 

Gas- check  pad. 

Vent. 

Hinge-pin. 

Rotating-crank. 

Translating-roller. 

Tray. 

Breech-plate. 

Slotted  sectors. 

Screw  sectors. 


Pinion-  and  gear-segment. 

Vent-bushing. 

Filling-in  disc. 

Exterior  ring. 

Interior  ring. 

Vent-cover. 

Rotating-crank  catch. 

Obturator-spindle. 

Obturator-spindle  nut. 

Locking-nut. 

Translating-stud. 

Guide-rails  of  tray. 

Tray-latch. 

Securing-latch 

Securing-latch  catch. 

Rotating-ring. 

Rotating-piniorio 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


45 


THE   GUNNER'S  EXAMINER. 


NOMENCLATURE  AND   GENERAL  DESCRIPTION.  47 


THE  GUNNER'S  EXAMINER. 


NOMENCLATURE  AND  GENERAL   DESCRIPTION. 


49 


THE   GUNNER'S  EXAMINER. 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


\\     f 


THE   GUNNER'S  EXAMINER. 


NOMENCLATURE  AND   GENERAL  DESCRIPTION. 


53 


54 


THE   GUNNER'S  EXAMINER. 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


55 


THE   GUNNER'S  EXAMINER. 


(Continued  from  Q.   on  page  40). 

For  continuous-motion  or  "Stockett"  mechanism  the  following: 


Spiral-gear. 

Crank. 

Worm-shaft. 

Worm. 

Worm-wheel. 

A.  See  Figs,  i,  2,  3,  4,  23. 


Breech  Block 


Tray  Latch 
Jtay  Latch  Catch 


Catch-bolt. 
Spring-bolt. 
Tray-latch  catch. 
Spindle-ball  bearing. 


Hinge  Pin 
Spiral  Gear 
.Geai  Segment 
-Tray 
Worm  Shaft 


Worm  Wheel 


CONTINUOUS  MOTION 

BREECH  MECHANISM. 
FIG.  23. 

Q.  Point  out  or  describe  the  location  of  the  following  parts 


of  the  5"  R.F.  breech  mechanism: 

Block-carrier. 

Hinge-pin. 

Spindle-key. 

Latch-bolt. 

Latch-lever. 

Lever. 

Pinion. 

Breech-block. 

Gear-segment. 

Vent-bushing  (copper). 

Exterior  split  ring  (front). 

Exterior  split  ring  (rear). 

Interior  split  ring. 


Gas-check  pad. 

Filling-in  disc. 

Tripping-stud. 

Latch-bolt  seat. 

Slide-housing. 

Slide-stop. 

Slide. 

Slide-handle. 

Contact-plate. 

Firing-leaf. 

Circuit-breaker  housing. 

Circuit-breaker  spring. 

Circuit-breaker  contact-pin. 

Firing-cable. 


A.  See  Figs.  24  and  25. 

Q.  Point  out  or  describe  the  following  parts  of  the  4.7-inch 
quick-firing    breech    mechanism:     Carrier-link,    spindle,    hand- 


NOMENCLATURE  AND  GENERAL   DESCRIPTION. 


57 


locking   lever,   firing-pin,   spring-catch,    sliding-block,   retaining- 
nut,  bolt. 

A.  See  Figs.  26  and  27. 

5'R.F.  GUN.    SHOWING    BREECH  MECHANISM. 


FIG.  24. 

Q.  Explain  briefly  how  a  breech-block  of  a  heavy  gun  or 
mortar  is  dismantled. 

A.  The  breech  being  open,  remove  the  locking-nut  and  spin- 
dle-nut, place  a  block  of  wood  against  the  spindle  and  gently 
hammer  the  mushroom  head  free  from  the  gas-check  pad,  then 


58  THE  GUNNER'S  EXAMINER. 

remove  it  by  hand.  Pry  the  exterior  and  interior  split  rings  free 
from  the  gas-check  pad  and  remove  them,  also  the  nlling-in  disc. 
The  spindle-washers  can  be  removed  at  any  time.  The  parts 
are  assembled  as  follows:  Adjust  in  the  following  order:  the  gas- 

5"  R.F.  GUN  AND  BREECH   MECHANISM. 


Pistol  Grip 


FIG.  25. 

check  pad,  exterior  and  interior  split  rings,  filling-in  disc,  and 
spindle-washers.  The  spindle-washers  must  be  put  on  after  the 
spindle  is  put  in.  Then  gently  insert  the  spindle  and  screw  on 
the  locking-  and  spindle-nuts  as  prescribed  for  adjusting  the 
gas-check  pad. 


NOMENCLATURE  AND  GENERAL   DESCRIPTION. 


59 


6o 


THE   GUNNER'S  EXAMINER. 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


61 


Q.  Point  out  or  describe  the  following  parts  of  the  one-pounder 
aubcaliber  tube  for  the  12"  B.  L.  R.,  model  1895: 

Gun. 

Adapter  clamp-wedge. 
Clamp- wedge  screw. 
Thread  clamp-screw. 
Rear  adapter. 
Center  support. 

A.    See  Fig.  28. 


Front  adapter. 
Adjusting- wrench. 
Clamping-wrench. 
Locating-gauge. 
Clip-extractor. 
Obturator  spindle-plate. 


ONE-POUNDER  SUBCALIBER  TUBE. 


Adapter  Clamp  Wedge  Clamp  Wedge  Sere 


T 


Clamping  Wrench 

FIG.  28. 


Q.  How  should  gas-check  pads  be  adjusted  before  firing? 
A.  First :  Close  the  breech. 


62 


THE  GUNNER'S  EXAMINER. 


Second:  Loosen  spindle  and  locking-nuts. 
Third:  Rotate  block  half-way. 

Fourth:  Tighten   spindle   and   locking-nuts  in   the   usual 
manner,  rotate  the  breech-block  home,  and  pad  is  adjusted. 
Q.  How  far  should  a  projectile  be  rammed  ? 
A.  Until  the  zero  of  the  brass  ring  on  the  rammer  comes 
flush  with  the  face  of  the  breech-plate.     (See  Fig.  29.) 


'A"  fc 


SCALE  ON   RAMMER,  TO  INDICATE 

PROPER  TRAVEL  OF  PROJECTILE 

FOR  8-1 0-1 2" RIFLE  AND 

12-MORTARS 


Scale 


Center  Line  of  Gun 


'A" 


FIG.  29. 

Q.  Describe  how  to  set  the  azimuth  indicator-plate  for  a 
given  azimuth. 

A.  Traverse  the  gun  until  the  mark  on  the  indicator-plate 
representing  the  number  of  hundredths  is  opposite  the  mark  on 
the  azimuth  circle  representing  the  number  of  degrees.  In  Fig. 
30  the  gun  is  set  at  io4°.o5. 


Racer 


Scale  of  "Hundredths  of  one  Degree' 
Gun.  Reads  104?05 


FIG.  3°- 


NOMENCLATURE  AND   GENERAL   DESCRIPTION.  ^ 

Q.  How  do  you  repack  a  stuffing-box? 

A.  If  any  of  the  old  packing  is  used,  it  should  be  put  in  after 
the  new.  See  that  the  stuffing-boxes  are  well  cleaned  and 
oiled. 

Put  on  the  piston-rod  one  ring  of  i-inch  Oarlock's  "water- 
proof hydraulic"  packing,  and  force  it  well  to  the  bottom  of  the 
stuffing-box  by  a  wooden  stick  and  mallet.  Treat  each  layer 
of  packing  in  a  similar  manner,  being  careful  to  break  joints 
until  five  rings  of  new  packing  have  been  inserted,  or  an  equal 
amount  of  new  and  old  when  any  of  the  latter  is  used.  Place  the 
gland  on  the  follower,  enter  them  together  in  the  box  and  screw 
up  the  follower. 

No  more  force  should  be  used  on  the  spanner-wrench  than 
that  of  two  men,  and  generally  that  of  one  man  is  sufficient.  The 
addition  of  the  pipe  to  the  end  of  the  spanner- wrench  should 
not  be  permitted. 

Q.  How  do  you  remove  old  packing  from  recoil-cylinders? 

A.  Remove  the  gland  and  follower  (using  new  extractor,  to 
be  furnished  by  the  Ordnance  Department).  Close  the  extractor 
around  the  piston-rod  and  insert  the  locking-pin.  Turn  the 
extractor  to  the  left,  with  pressure  on  the  packing,  until  the  needles 
are  firmly  engaged  in  the  packing.  Draw  the  packing  out4 
turning  slowly  to  the  left.  In  the  case  of  a  box  with  interior  thread, 
and  if  the  ring  is  tight,  it  should  be  unscrewed  and  not  stripped 
out  by  the  thread,  because  unless  unscrewed  it  would  catch  upon 
and  be  injured  by  the  thread. 

Extractor-bars  are  provided  to  be  used  for  starting  the  packing 
from  its  seat,  and  by  inserting  the  toes  of  the  bar  in  the  rack-teeth 
and  prying  over  the  edge  of  the  box,  being  careful  not  to  injure 
the  thread. 

Q.  What  is  the  object  of  the  throttling- valve  ? 

A.  To  regulate  the  flow  of  oil  from  the  front  to  the  rear  of  the 
recoil-cylinders.  (See  Fig.  31.) 

Q.  What  precautions  should  be  taken  where  the  throttling- 
valve  is  provided  ? 


THE  GUNNER'S  EXAMINER. 


NOMENCLATURE  JND  GENERAL  DESCRIPTION  65 

A.  That  there  is  a  lock  on  the  valve  to  prevent  any  one  from 
changing  the  setting  without  authority. 

Q.  Give  some  general  directions  for  the  care  and  preservation 
of  guns  and  gun-carriages. 

A.  All  guns  and  carriages  should  be  elevated  and  traversed 
to  their  full  limits  daily.  Ordinarily  a  gun  and  carriage  should  be 
painted  at  least  once  a  year.  However,  climatic  conditions  may 
vary  this  rule.  Sperm-oil,  cosmic  or  light  slushing  oil  should  never 
be  applied  to  a  surface  that  has  a  suspicion  of  grit,  moisture,  or 
rust  upon  it.  Brass  gearing  should  have  a  thin  film  of  sperm- 
oil  or  synovial  oil  on  it.  All  oil-holes  and  recoil-cylinders  should 
be  examined  daily  at  the  beginning  of  drill.  Special  attention 
should  be  given  to  grease-cups  on  disappearing  guns  to  see  that 
they  function  properly.  Retraction-ropes  should  be  kept  oiled 
and  cleaned.  No  part  of  the  carriage  should  at  any  time  be 
allowed  to  rust,  and  if  the  carriage  is  to  remain  unused  for  short 
intervals,  all  bright  and  bearing  parts  should  be  covered  with  a 
thick  coat  of  light  slushing  oil  or  cosmic.  If  the  carriage  is  to 
remain  unused  for  long  intervals,  the  cosmic  should  be  mixed 
with  25  per  cent  of  resin.  The  mixture  is  well  adapted  for  the 
purpose,  but  must  be  renewed  from  time  to  time.  The  rollers 
and  roller-paths  should  be  cleaned  and  covered  with  slush  oil,  and 
the  space  between  the  dust-guard  and  base-ring  should  be  filled 
with  waste  or  oakum  to  keep  out  dust,  and  wrench-holes 
inside  base-ring  should  be  plugged  tightly  with  fitted  wooden 
blocks. 

To  oil  bore,  use  is  made  of  an  ordinary  counter-brush  secured 
to  the  end  of  a  rod  and  provided  with  a  half-disc  of  wood  to  keep 
the  brush  against  the  bore.  By  this  means  any  required  thickness 
of  the  mixture  may  be  applied.  The  brush-rod  is,  for  the  rifles, 
fitted  with  a  socket  for  connecting  it  with  the  special  sponge-staff. 
For  mortars  the  brush  is  supplied  with  a  special  handle.  As  a 
rule,  the  cosmic  and  resin  mixture  can  be  sufficiently  removed 
from  the  bore  for  firing  by  using  the  scraper  alone,  this  being  a 
semicircular  disc  of  iron. 


66  THE   GUNNER'S  EXAMINER. 

Q.  Describe  throttling  bars. 

A.  Bars  of  steel  bolted  on  the  sides  of  recoil  cylinders.  (The 
bolt  heads  can  be  seen  on  the  outside  of  the  cylinders.) 

The  piston  head  is  slotted  to  receive  the  bars  as  shown  in 
Fig.  31,  and  the  bars  are  thicker  at  one  end  than  at  the  other, 
this  varies  the  amount  of  oil  that  can  pass  through  the  piston 
head  slots  and  therefore  the  pressure  keeps  uniform. 

CARE   OF   GUNS   AND   CARRIAGES. 

(Extract  from  War  Department,  1905.) 
CIRCULAR  ) 
No.  48.     J 

Light  slushing-oil  will  be  used  on  the  different  parts  of  breech 
mechanisms,  including  the  threads  on  the  block  and  in  the  breech 
recess,  in  bores  of  guns,  and  on  all  other  bright  steel  or  iron  surfaces 
of  mobile  and  seacoast  armament,  as  a  preservative  when  the 
material  is  to  remain  unused  for  an  appreciable  length  of  time. 
The  slushing-oil  will  replace  synovial  oil  as  a  lubricant  for  cross- 
head  guides,  etc.,  which  should  be  given  a  light  coating  only. 
The  use  of  light  slushing-oil  as  a  lubricant  on  breech  mechanisms, 
including  the  threads  on  the  block  and  in  the  breech  recess,  is 
forbidden:  synovial  oil  will  be  used  exclusively  for  lubricating 
the  different  surfaces  of  breech  mechanisms,  including  the  threads 
on  the  block  and  in  the  breech  recess,  on  translating- screws  and 
rollers,  and  in  all  oil-holes  and  on  gears,  etc.,  of  carriages.  Num- 
ber 4^  lubricant  only  will  be  used  in  grease- cups.  If  exposed  to 
rain  within  thirty  hours  after  its  application,  all  surfaces  should 
be  carefully  examined  and  recoated  if  necessary.  It  can  be  ap- 
plied by  means  of  paint-brushes  known  as  sash-tools  No.  6, 
issued  for  that  purpose.  Except  in  very  cold  weather  it  can  be 
applied  in  a  thin  uniform  coat  by  using  the  brush,  as  when  paint- 
ing. During  cold  weather  it  should  be  applied  by  stippling — i.e., 
lightly  tapping  the  surface  with  the  end  of  the  brush — the  brush 
being  held  perpendicular  to  the  surface  to  be  covered.  It  can  be 
applied  to  the  bores  of  guns  by  means  of  the  slush -brush  issued 


NOMENCLATURE  AND   GENERAL   DESCRIPTION,  67 

for  the  purpose.  In  cold  weather  it  should  be  warmed  before 
being  applied  to  the  bores  of  guns.  In  all  cases  it  should  be  applied 
in  a  thin  coat,  since  this  is  all  that  is  necessary  to  give  good  pro- 
tection. 

This  oil  can  be  readily  removed  by  the  use  of  burlap  or  waste 
dipped  in  kerosene  oil.  Lye  dissolved  in  hot  water  and  used 
while  hot  will  also  remove  it,  but  not  as  satisfactorily  as  kerosene 
oil.  In  order  to  reduce  the  amount  of  kerosene  oil  to  be  used 
for  its  removal,  a  thick  coating  of  slushing-oil  when  present  should 
first  be  removed  with  a  scraper  before  applying  the  kerosene. 

Water  without  the  addition  of  lye  or  kerosene  should  be 
used  for  cleaning  bores  of  guns  after  firing.  They  should  be 
permitted  to  drain  and  then  be  wiped  dry  before  applying  the 
slushing-oil. 

Before  applying  the  slushing-oil  to  any  surface  it  should  be 
thoroughly  cleaned  so  as  to  be  free  from  rust,  water,  kerosene 
oil,  lubricating-oil,  etc.,  as  their  presence  will  cause  rusting  under- 
neath the  slushing-oil.  If  applied  to  an  oiled  surface,  the  slushing- 
oil  has  been  found  to  run  off  when  heated. 

On  account  of  the  superior  protection  afforded  by  this  ma- 
terial it  will  not  be  necessary  to  completely  remove  it  for  in- 
spection purposes  as  frequently  as  has  been  found  necessary 
with  the  protecting  materials  heretofore  used.  Its  frequent 
removal  from  a  limited  area  will  serve  as  an  indication  of  the 
protection  which  is  being  afforded. 

III.  Mortars  will  hereafter  be  dismounted  from  their  car- 
riages once  every  twelve  months,  and  the  trunnions  and  trun- 
nion-beds thoroughly  cleaned,  including  the  oil-grooves  in  the 
trunnion-bed  liners. 

The  counter- recoil  springs  will  at  the  same  time  be  dismounted, 
the  old  paint  removed,  and  each  spring  given  two  coats  of  new 
paint.  The  spring  should  not  be  reassembled  until  the  paint  is  dry. 

By  order  of  the  Acting  Secretary  of  War: 

J.   C.   BATES, 

Major-General,  Acting  Chief  of  Staff. 


68  THE   GUNNER'S  EXAMINER. 

Q.  Describe  the  general  parts  of  the  throttling-valve  and  how 
it  operates. 

A.  The  two  equalizing-pipes  connecting  the  front  and  rear 
of  opposite  recoil-cylinders  have  a  pipe  connecting  them;  if  this 
pipe  is  open  completely,  oil  can  move  freely  from  the  front  to 
the  rear  of  the  cylinders.  If  it  be  closed  partly  by  a  valve  called 
the  throttling-valve,  much  less  oil  will  pass  this  way.  Thus,  by 
regulating  the  adjustment  of  this  valve,  the  recoil  of  the  gun  is 
regulated.  It  is  seen  that  the  throttling-bars  work  with  the 
throttling-valve.  (See  Fig.  31.) 

Q.  How  much  oil  should  be  removed  from  recoil-cylinders 
having  the  filling-plugs  on  the  top  of  the  cylinders  ? 

A.  i2-inch  disappearing  carriages,  all  models,  3    gallons, 
lo-inch  disappearing  carriages,  all  models,  ij  gallons. 
8-inch  disappearing  carriages,  all  models,  i    gallon. 
6-inch  disappearing  carriages,  model  1898,  J  gallon. 

Q.  Where  new  filling-plugs  have  been  inserted  explain  how 
the  cylinders  are  filled. 

A.  For  full  charges  remove  the  two  filling-plugs  (one  from  each 
cylinder),  pour  oil  into  one  filling-hole  until  it  flows  out  of  the 
hole  in  the  other  cylinder,  wait  a  moment  to  allow  the  oil  to  settle, 
and  examine  for  any  pocketed  air  or  any  temporary  obstruc- 
tion. If  necessary,  pour  in  more  oil  until  the  oil  is  observed  to  be 
in  both  cylinders  up  to  the  level  of  the  filling-holes,  then  insert 
the  screw-plugs  without  removing  any  oil. 

Q.  Prior  to  firing,  what  should  be  done  to  the  bore  of  the  gun  ? 

A.  Prior  to  artillery  practice  the  bore,  including  the  powder- 
chamber,  of  each  piece  to  be  used  in  practice  will  be  thoroughly 
cleaned  and  freed  from  lubricant  before  any  shot  is  fired. 

Q.  How  is  powder  residue  removed  after  firing? 

A.  After  firing  the  bore  may  be  cleaned  by  using  a  sponge 
covered  with  burlap  well  saturated  with  water.  The  bore  should 
then  be  permitted  to  drain  and  thoroughly  dry  before  being  oiled. 

Q.  If  any  rust  has  accumulated  on  a  bearing  part,  would  you 
use  sandpaper  to  remove  it? 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


69 


RECOIL    CYLINDER 
FOR  MORTARS 


Piston 


Oil  Cavity 
Plugs 


iston  Head 


Holes  for  oil  to 
pass  through 


A.  The  use  of  sandpaper  is  forbidden,  and  emery-cloth  No.  i, 
being  coarse  enough  for  any  ordinary  rusting,  should  be  used,  the 
rust  being  softened  if  necessary  by  kerosene. 

Q.  Describe  the  recoil- 
cylinder  for  mortars  and  its 
action. 

A.  Fig.  32.  When  the 
mortar  is  fired,  the  piston  is 
forced  down,  causing  the 
piston-head  to  force  oil 
through  the  oil-holes  shown 
on  the  left  of  Fig  32.  This 
oil  passes  through  the  oil- 
cavity  upward  and  in  rear  of 
the  piston-head.  By  opening 
or  closing  these  oil-passages 
by  withdrawing  or  inserth.'g 
different-sized  plugs  the  fric- 
tion, hence  the  recoil,  can  be 
adjusted. 

Note. — For  steel  mortars 
model  '91  the  plugs  are  as  in 
Fig.  32;  that  is,  from  top  to 
bottom:  closed,  ^,  o,  o,  J, 
closed,  closed.  For  C.  I. 
mortars  '91 :  c.,  J,  o,  o,  J,  c., 
c.  For  model  '96  c.,  ^,  J, 

o,  J. 

Q.  What  are  "  grease-cups  "? 

A.  Brass  cups  placed  on  the  trunnions  of  guns  to  lubricate  or 
oil  the  trunnions  and  trunnion-beds. 

Q.  How  are  they  filled  and  adjusted? 

A.  Fill  up  to  the  bevel  edge  of  the  cup  with  the  special  oil 
provided  by  the  Ordnance  Department.  The  cup  is  then  put  on 
and  screwed  down  until  the  plunger  sticks  out  one  quarter  of  an 
inch.  By  doing  this  a  spring  bearing  on  the  plunger  is  forced  to 


Plugs 


Holes  for  oil  to 
pass  through 


Equalizing 
Pipe, 


Piston 


FIG,  32. 


*o  THE   GUN  NEKS  EXAMINER. 

act,  causing  the  plunger  to  press  upon  the  oil,  forcing  it  into  the 
grooves  and  channels  cut  under  the  trunnions.  The  plunger 
should  be  kept  at  this  distance  (J")  from  the  cap  by  screwing 
down  the  cap  from  day  to  day.  When  the  plunger  will  no  longer 
be  pressed  out  it  is  known  that  no  more  oil  is  in  the  cup,  and  it 
should  be  refilled. 

Q.  State  some  rules  to  be  observed  in  painting  guns  and 
carriages. 

A.  The  gun  is  painted  gray,  and  the  carriage  olive-green. 
These  are  the  only  colors  authorized.  The  entire  surface  of  the 
gun  is  painted  except  where  the  console,  or  tray,  touches  the  gun. 
Two  coats  annually  are  usually  allowed. 

Bronze  trays  will  not  be  painted.  Steel  trays,  excepting  the 
upper  and  front  surfaces  and  guide-rails,  will  be  painted  the 
same  color  as  the  gun.  No  parts  of  the  breech-block  or  mech- 
anism will  be  painted.  The  unpainted  surfaces  will  be  kept 
clean  and  bright  with  rottenstone  and  oil  or  "  Putzpomade." 

All  steel  and  iron  non-bearing  surfaces,  both  inside  and  out, 
will  be  painted.  This  includes  the  exposed  parts  of  shafts  (except 
squared  ends),  bottom  plate  of  counterweight,  ladders,  cross-heads, 
cranks,  not  handles),  cross-head  pawls  (except  teeth),  and  large 
bronze  pieces,  including  web  and  spokes  of  wheels  and  cylinder- 
heads. 

The  following  parts  are  not  painted:  All  wearing  or  bearing 
surfaces,  which  includes  the  handles  of  hand-wheels  and  cranks, 
teeth  of  all  gear-wheels,  teeth  of  cross-head  pawls,  teeth  of  cross- 
heads,  elevating-rack  guides,  rollers  and  surfaces  on  which  they 
travel,  piston-rods,  crosshead-guides,  etc. 

The  bronze  sight-holders  will  not  be  painted,  nor  will  the 
azimuth  and  elevating-scales  and  pointers  and  the  followers  of 
the  stuffing-boxes;  these  parts  will  be  kept  clean  and,  with  the 
exception  of  the  sight-holders,  will  also  be  kept  bright  with  rotten- 
stone  and  oil  or  "Putz-pomade." 

The  raised  surfaces  of  letters  and  rims  of  direction  and  name- 
plates  are  to  be  kept  clean  and  bright;  the  background  of  these 
plates  will  be  painted  the  same  color  as  the  carriage. 


NOMENCLATURE  AND   GENERAL  DESCRIPTION.  71 

Name-plates  shall  never  be  removed  in  painting  the  carriage. 
This  is  prohibited  by  orders. 

Q.  How  is  old  paint  removed? 

A.  Dissolve  one  pound  of  concentrated  lye,  powdered  form, 
in  six  pints  of  hot  water,  and  slake  in  enough  lime  to  give  the 
solution  the  consistency  of  paint.  Use  the  solution  freely  mixed, 
and  apply  to  the  parts  where  paint  is  to  be  removed,  with  a  brush 
preferably,  or  with  waste  tied  on  the  end  of  a  stick.  When  the 
solution  begins  to  dry  on  the  surface  use  a  scraper  to  remove  the 
old  paint,  and  complete  the  cleaning  of  the  surface  with  a  mop  and 
water.  If  one  application  is  not  sufficient  to  loosen  the  paint, 
apply  a  second  coat.  Before  applying  the  new  coat  of  paint 
wash  the  surface  with  liquid  made  by  dissolving  one  half  pound 
of  washing-soda  in  eight  quarts  of  water,  and  wipe  dry.  Let 
stand  a  sufficient  length  of  time  to  have  all  parts  thoroughly  dry 
before  painting. 

Q.  Should  oil  or  grease  ever  be  applied  to  the  surfaces  of 
electrical  contacts  on  a  gun  or  carriage? 

A.  No.  Grease  or  oil  acts  as  an  insulator  and  prevents  the 
current  from  passing  the  contacts. 

Q.  Point  out  or  describe  the  following  parts  of  a  battery: 
Emplacement,  parapet,  traverse,  parados,  exterior  slope,  interior 
crest,  interior  slope,  superior  slope,  interior  wall,  gun-platform, 
truck-platform,  loading-platform. 

A.  See  Fig.  14. 

Q.  Explain  how  to  adjust  the  firing  mechanism. 

A.  Insert  the  -safety  bar  in  the  safety-bar  notch  of  the  slide 
housing.  Slip  the  slide  housing  over  the  spindle,  at  the  same 
time  inserting  the  safety  bar  in  its  recess  in  the  breech  block. 
Press  both  home  firmly.  Slip  on  the  yoke,  pressing  down  until 
the  notch  above  the  ring  is  just  visible.  (In  this  operation  it 
may  be  necessary  further  to  adjust  the  spindle  if  the  yoke  does 
not  go  on  completely,  and  the  gas-check  pad  may  have  to  be 
flattened  for  this  purpose.) 

Put  the  ejector  in  place  with  the  ejector  raised  and  the  slide 
stop  pulled  out.  Place  the  slide  in  position. 


7  2  THE   GUNNER'S  EXAMINER. 

Q.  When  the  weather  is  freezing  what  should  be  done  to  the 
recoil-cylinders  before  firing  service  charges? 

A.  A  small  amount  of  oil  should  be  taken  out  and  a  reduced 
charge  fired,  then  fill  the  cylinders  and  fire  full  service. 

Q.  Where  should  primers  and  fixed  ammunition  be 
kept? 

A.  Separate  place  from  powder:  never  in  the  magazine. 
Primers  should  be  kept  preferably  in  the  ammunition-chests,  and 
fixed  ammunition  in  the  shot-room. 

Q.  How  is  the  weight  of  a  cored  shot  or  plugged  shell  brought 
to  standard  weight? 

A.  By  adding  sand  mixed  with  iron  filings,  water,  or  sawdust, 
according  to  the  degree  of  increase  required. 

Q.  How  should  throttling-bar  bolts  be  adjusted? 

A.  First  loosen  them  slightly,  scrape  away  any  paint  that 
clogs  them,  and  then  tighten  them  to  full  limit. 

Q.  What  is  a  priming-charge,  and  where  is  it  placed? 

A.  A  small  charge  of  black  powder  in  both  front  and  rear  of 
every  section  of  cartridge. 

Q.  Should  the  trunnion-seats  of  sight-standards  be  polished? 
If  not,  why  not  ? 

A.  No.  Polishing  wears  away  the  brass  and  throws  the  sight 
out  oi  adjustment.  They  should  be  wiped  clean,  however. 

Q.  Is  the  removal  of  the  name-plates  or  sight-brackets  author- 
ized at  any  time  ? 

A.  No. 

Q.  How  do  you  test  the  adjustment  of  the  azimuth  indicator  ? 

A.  Insert  the  bore-sights,  traverse  the  gun  until  the  line  of 
sight  through  the  front  and  rear  bore-sights  intersects  a  datum 
point  whose  azimuth  is  known.  If  the  indicator  reads  this 
azimuth,  the  gun  is  in  azimuth. 

Q.  How  do  you  test  the  level  of  a  carriage? 

A.  If  the  trunnion  sight -bracket  is  correctly  adjusted,  place 
the  telescopic  sight  upon  it,  set  the  sight  and  gun  at  zero  elevation, 
and  traverse  the  carriage  to  the  full  limits.  If  the  bubble  in  the 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


73 


telescope-level  remains  stationary,  the  carriage  is  level.     If  not, 
adjust  by  turning  the  leveling-bolts. 

POWDERS,  PROJECTILES,  PRIMERS,  AND    FUSES. 

Q.  How  do  you  distinguish  the  following  powders:  Musket, 
sphero-hexagonal,*  brown  prismatic,  black  prismatic,  and  smoke- 
less. 

A.  Musket  is  black  and  very  fine  grained.  Sphero-hexagonal 
is  black  and  in  the  shape  of  a  small  ball  with  a  six-sided  ring 
around  it.  Brown  prismatic  is  brown,  in  the  form  of  a  six-sided 
prism  with  a  hole  in  the  center.  All  smokeless  powder  has  the 
appearance  of  translucent  celluloid  and  smells  of  ether.  This 
powder  grades  in  size  according  to  the  caliber  of  the  gun,  and  has 
for  large  guns  a  cylindrical  form  with  small  holes  running  length- 
wise in  it.  (See  Fig.  33.) 


SPHERO-HEXAGONAL. 


BROWN   PRISMATIC. 


MORTAR. 


12" 


10"  8"  6" 

SMOKELESS  POWDER. 
FIG.  33- 


5" 


3" 


Note— The  smokeless  powder  used  in  the  U.  S.  Coast  Artillery 
is  made  out  of  ordinary  cotton  waste.  The  process  of  manufac- 
ture is  briefly  as  follows:  The  cotton  waste  is  first  thoroughly 

*  Sphero-hexagonal  is  no  longer  used. 


74  THE   GUNNER'S  EXAMINER. 

washed,  cleaned,  picked,  and  then  put  through  shredding-  and 
cutting-machines.  It  is  then  dried  in  ovens  for  many  hours.  It 
is  then  placed  in  pots  and  a  mixture  of  strong  nitric  and  sulphuric 
acid  is  poured  over  it.  It  is  then  washed  in  running  water  for 
many  more  hours.  It  is  now  called  "guncotton."  It  is  then 
dissolved  with  a  mixture  of  alcohol  and  ether  and  put  under  a 
hydraulic  press.  On  coming  out  of  the  press  it  looks  like  yellow 
gum.  It  is  then  forced  through  different  sized  dies,  and  in  this 
shape  looks  like  macaroni.  It  is  then  cut  into  various  lengths 
and  sizes,  according  to  the  caliber  of  gun  for  which  it  is  to  be  used. 

Q.  Give  the  weight  of  charge,  weight  of  projectile,  and  initial 
velocity  of  the  piece  to  which  your  company  is  assigned. 

A.  See  table  on  page  75.  (Ref.  Ordnance  Department,  G.  O. 
9,  W.  D.  '08.)  Slight  variations  from  the  requirements  of  this 
table  will  be  permitted;  but  it  is  desired  that  these  requirements 
shall  be  fulfilled  as  nearly  as  practicable. 

Q.  Name  the  different  kinds  of  primers. 

A.  Common  friction,  common  electric,  obturating  friction, 
obturating  electric,  and  combination  electric  friction. 

Q.  Explain  the  action  of  the  common  friction  and  the 
obturating  friction  primer. 

A.  Its  action  consists  in  the  friction  of  a  saw-tooth  wire  being 
pulled  through  a  portion  of  mercuric  fulminate,  which  explodes 
and  ignites  a  small  charge  of  powder  in  the  primer,  which  in 
turn  ignites  the  main  charge  in  the  gun.  (See  Figs.  34  and  35.) 

Q.  Explain  the  action  of  the  common  and  obturating  electric 
primer. 

A.  Two  insulated  wires  entering  the  primers  are  joined 
by  a  platinum  wire.  (A  little  guncotton  is  sometimes  imbedded 
around  the  platinum  wire.)  The  current  heats  the  platinum, 
which  ignites  a  small  charge  of  powder  or  fulminate,  if  it  be  a 
common  electric,  in  the  primer,  which  ignites  the  main  charge. 
(See  Figs.  36  and  37.) 

Q.  Explain  the  action  of  the  combination  electric  friction  primer. 

A.  It  is  a  combination  of  the  two  above  principles,  except  that 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


75 


TABLE  OF  CHARGES,  VELOCITIES,  ETC.,  FOR  RAPID-FIRE  AND  SEACOAST  GUNS. 

Weights  of  projectiles,  powder  charges,  muzzle  velocity,  and  pressure  for  rapid-fire 
and  seacoast  guns,  service  and  practice  charges. 


1 

1 

"8 

0 

M 

fl 

O 

•8 

1 

-i<N 

1 

| 

bi 

3 

-g 

I 

1 

S§ 

1 

1 

1 

1 

S 

g 

. 

J-T3 

js 

oi 

•S 

1 

Q 

Q 

'S  0) 

-o 

I 

g  " 

C    • 

Q 

•s 

Jg 

6  . 

6  . 

C  js 

23  ^-i 

H 

t> 

3*S 

OOi 

^3 

^O5 

jaS 

P 

•r 

! 

I2 

I3 

3 

S 

i 

i 

18 

Weight  of  projectile 
(Ibs  ) 

1  .06 

18 

6 

15 

15 

33 

45 

106 

58 

58 

Weight     of     charge 

(Ibs.): 

Smokeless  — 

Nitroglycerin.  . 

1.25 

f    40-7.5 

Nitrocellulose  .  .  . 

*2.5 

*7 

1.35 

5 

6.06 

7.5 

45-10.5 

19 

16.5 

23 

[50-10.5 

f    40-5.5 

Cordite        .    . 

J    45-8  2 

13.3 

I    50-8.2 

Brown  prismatic 
Muzzle  velocity  (f.s.): 

12.0 

Smokeless  

2100 

750 

2400 

2600 

2600 

2300 

2600 

2600 

f  40-2150 

} 

Cordite  

\  45-2570 

12150 

I  50-2600 

Brown  prismatic. 
Maximum  permissible 

2000 

pressure  (pounds  per 
square  inch)  

25000 

18000 

37460 

34000 

41000 

34000 

34000 

34000 

38000 

36000 

u 

"8 

"go 

«t-^ 

1 

o 

o 

o 

CM 

°o 

o 

1 

li 

k2<* 

1 

o 

Ji 

i 

T—   9* 

^  GO 
O  QT 

S 

(-[     . 

rcc 

--a 

m 

•^0 

* 

^.^ 

"is 

d^ 

61 

#  i 

ti 

<£  i 

^ 

s  i 

§g 

-fl05 

-d 

J^OO 

"«® 

-goo 

18 

-goo 

'o* 

3*" 

to 

1 

00 

1 

Is 

C  GO 

J8 

s 

I"8 

Weight  of  projectile 

(Ibs  )             ... 

106 

106 

316 

604 

604 

1046 

1046 

82^ 

[    1046 

824 

1046 

Weight    of    charge 

(Ibs.): 

Smokeless  — 

Nitrocellulose  .  .  . 

29.75 

39.1 

80 

155 

205 

275 

325 

3: 

J        33 

62 

54 

Brown  prismatic. 

135 

280 

490 

7, 

>        75 

105 

105 

Muzzle  velocity  (f.s.): 

Smokeless  

2600 

2600 

2200 

2250 

2250 

2250 

2250 

105( 

)      910 

1300 

1050 

Brown  prismatic 

1975 

2025 

2025 

102( 

)      900 

1150 

1020 

Maximum  permissiple 

pressure  (pounds  per 
square  inch)  

38000 

36000 

38000 

38000 

38000 

38000 

38000 

2750( 

)  27500 

33000 

33000 

*  The  minimum  charge  for  mortars  is,  according  to  an  endorsement  from  the  Chief  of 
Ordnance,  18  Ibs. 


THE   GUNNER'S  EXAMINER 


OBTURATING  FRICTION, 
lye 


COMMON  FRICTION. 

Motion  Pellet 


Seriated  Wire 
opper  Body 


Powder 
losing  Cup 


rass  Body 


•Screw  Threads 

'riction  Pellet 

Serrated  Wire 

Powder 

Brass  Closing  Cup 


FIG.  34- 
COMMON  ELECTRIC, 


FIG.  35. 


Powder 
Body 
Platinum  Wire  Bridge 

Wax 

-Insulated  Copper  Wires 


OBTURATING  ELECTRIC. 

£ Insulated  Copper  Wires 

Body 


Screw  Threads 


Platinum  Wire  Bridge 
Closing  Cup 


FIG.  36. 


FIG.  37- 


NOMENCLATURE  AND   GENERAL   DESCRIPTION.  7? 

in  the  electric  feature  there  is  no  return*  wire  in  the  combination 
primer.  The  current  comes  in  through  the  stem  from  the  copper 
contacts  on  the  firing  mechanisms,  heats  the  platinum,  etc.,  and 
goes  out  through  the  case  of  the  primer  to  the  breech-block  of 
the  gun,  thence  to  the  trunnion  and  to  the  other  pole  of  the  firing- 
battery.  This  primer  is  also  obturating.  (Fig.  38.) 
Q.  What  is  an  obturating-primer  ? 

A.  One  which  prevents  the  escape   of   powder- gas   through 
the  vent.     (It  need  not  necessarily  be  screwed  into  the  vent.) 
Q.  What  are  percussion- primers ? 

A.  Such  as  are  used  in  fixed  ammunition  and  go  off  by  the 
snap  of  the  firing-pin.     They  are  commonly  called  caps. 
Q.  What  are  high-  and  low-resistance  fuses  ? 
A.  A  high-resistance  fuse  is  one  that  requires  a  high  initial 
velocity  to  cause  the  plunger  to  be  released,  and  is  therefore  safer 
in  handling.     A  low-resistance  fuse  does  not  require  such  a  high 
initial  velocity  to  cause  it  to  act.     Low-resistance  fuses  are  pro- 
vided with  "  safety- wires. "     (See  Fig.   39.) 

Q.  What  fuses  are  used  in  the  United  States  service? 
A.  Frankfort  Arsenal  base  percussion,  point  percussion,  and 
combination.  The  first  two  are  of  either  high  or  low  resistance, 
and  vary  in  size  for  different  calibers  of  guns.  All  fuses  that 
are  not  "  centrifugal "  have  become  obsolete  for  all  calibres  above 
1.65",  except  the  combination  fuse,  but  those  on  hand  will  be  in 
service  until  used  up. 

Q.  How  are  fuses  inserted  to  make  a  tight  joint  ? 
A.  By  putting  a  special  preparation,  supplied  by  the  Ord- 
nance Department,  on  the  threads.     Never  use  red  lead. 

Q.  Describe  the  action  of  a  percussion-fuse  and  name  parts. 
A.  On  firing,  the  plunger-sleeve  is  forced  to  the  rear  and 
remains  in  this  position  during  flight.  On  striking,  the  plunger 
and  plunger-sleeve  are  forced  forward  and  the  prick-point  of  the 
plunger  strikes  the  fulminate  of  the  fuse;  this  ignites  the  priming 
charge  in  the  fuse,  which  ignites  the  charge  in  the  shell  (Fig.  39). 

NOTE. — There  is  a  new  fuse  now  prescribed  for  our  artillery  called  "  The  De- 
tonating Fuse."  No  one  is  permitted  to  take  this  fuse  apart  and  its  construction 
is  kept  secret. 


THE  GUNNER'S  EXAMINER. 


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NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


79 


Q.  Explain  the  action  of  the  combination  fuse  and  name  parts. 

A.  Before  firing  a  hole  is  punched  through  the  hole  on  the 

time-cone  corresponding  to  time  of  flight  at  which  it  is  desired 

FRANKFORD  ARSENAL  BASE  PERCUSSION  FUSES. 

Low.  HIGH. 


w— 


Body 

Closing-cap 

Primer  closing-screw 

Primer 

Tin-foil  disc 

Primer-shield 

Firing-pin  sleeve 

Firing-pin 

Split-ring  spring 

Locking-groove 

Brass-covering  disc 

Percussion  -  primer 
composition 

Magazine  powder- 
charge 

Safety- wire 

Vent 


Low  FUSE,  MODEL  1900. 


PLAN  OF  BASE  LOW  W. 
SHOWIMG  MARKING. 


FIG.  ,39- 

that  the  projectile  burst.  On  firing,  the  time-plunger  strikes 
the  firing-pin  for  the  time-train,  then  the  time-train  begins  to 
burn  from  the  point  where  the  hole  in  the  cone  was  made,  and 


8o  THE  GUNNER'S  EXAMINER. 

at  the  end  of  the  time  of  flight  the  flame  reaches  the  interior  of 
the  fuse,  thence  to  the  shell.  If  this  fails  or  it  be  desired  to  use 
the  fuse  as  a  percussion- fuse,  the.  action  is  as  in  an  ordinary 
percussion- fuse.  Combination  fuses  are  now  always  made  with 
the  centrifugal  arming  device  as  in  percussion.  (SeeFigs. 40  and  42 .) 

Q.  What  is  a  delayed-action  fuse  ? 

A.  One  which  does  not  explode  until  a  short  time  after  strik- 
ing. 

Q.  Explain  the  action  of  the  new  centrifugal  fuse. 

A.  This  fuse  can  act  only  when  a  rotary  motion  is  given  to 
it.  This  rotary  motion,  due  to  the  rotating  band,  causes  the 
plunger  to  bulge  away  from  the  center  into  two  parts;  when 
these  parts  separate  it  is  seen  from  Fig.  41  that  the  firing-pin 
takes  up  a  position  parallel  to  the  longer  axis  of  the  fuse  and 
its  point  is  almost  touching  the  friction  composition.  When 
the  projectile  strikes,  the  plunger  drives  the  firing-pin  into  the 
friction  composition.  The  action  is  then  the  same  as  in  the 
ordinary  percussion-fuse.  This  fuse  is  therefore  perfectly  safe  to 
handle,  transport,  or  use.  It  becomes  active  only  when  a  high 
rotary  motion  is  given  it.  (See  Figs.  41  and  42.) 

Q.  How  are  drill-primers  loaded  ? 

A.  Insert  a  serrated  wire  with  friction-pellet  in  the  body  of 
the  primer,  hold  it  in  position  with  the  assembling- tool,  screw  a 
rear  wire  or  bottom  wire  (depending  on  whether  it  is  an  old-  or 
new- model  vent)  fast  to  the  serrated  wire,  fill  with  musket- powder, 
and  close  with  a  brass  closing-cup,  using  the  assembling-tool. 

Q.  Name  the  different  kinds  of  projectiles  in  the  United 
States  service. 

A.  Solid  shot,  cored  shot,  shell,  shrapnel,  and  canister.     (See 

Fig.  43-) 

Q.  What  is  the  rotating-band  and  what  is  its  use  ? 

A.  The  copper  band  near  the  base  end.  It  is  forced  into 
the  grooves  of  the  rifling  and  causes  the  projectile  to  take  up  a 
rotary  motion  to  prevent  tumbling  during  flight. 

Q.  Why  are  some  projectiles  capped  ? 


NOMENCLATURE  AND   GENERAL  DESCRIPTION. 


Sr 


FRANKFORD    ARSENAL    TIME     PERCUSSION     OR     COMBINATION 
FUSE.     MODEL   1900. 


a  Body 

6!  Compressed  powder-ring 

b  Retaining-ring 

b2  Brass  ring 


Brass  cup     !•  Gas-check 

Felt  washer  J 

Time-train 

Time-train  cone 

C jne-cover 

Drawn-brass  waterproof  cover 

Soldering-strip 

Cap 

Clamping-nut 

Time-plunger 

Split-ring  spring 

Safety-pin 

Connecting-tube 

Powder-charge 

Powder-chamber  closing-screw 

Percussion-primer 

Tin-foil  discs 

Percussion-primer  composition 

Brass  cup 

Concussion  firing-pin 

Percussion  firing-pin  sleeve 

Percussion  safety- wire 

Percussion  firing-pin 

Dowel-pins  (2) 

Stud-pin 

Concussion-primer  composition 

Tin-foil  disc 

Vents (4) 

Split-ring  spring 

Wrench-hole 

Tin-foil  base-cover 

Bottom  closing-screw 

Base-vents  (8) 

Locking-groove 


FIG.  40. 


NOTE. — In  punching  fuse  see  that  pin  enters  up  to  shoulder  to  insure  penetra- 
tion of  cone  d. 

If  fired-  for  percussion-burst,  punch  at  maximum  time-setting  but  do  not  re- 
move safety-pin  *. 

Ignition  of  time-train  c  is  due  to  punched  hole  acting  as  vent  for  gases  from 
primer-charge  r  and  compressed  powder-ring  b. 


82 


THE  GUNNRR'S  EXAMINER. 


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NOMENCLATURE  AND   GENERAL  DESCRIPTION.  83 

A.  Experimental  tests  have  shown  that  it  will  penetrate 
armor-plate  deeper  than  those  not  capped. 

Q.  What  is  the  difference  between  shrapnel  and  canister? 

A.  Shrapnel  is  composed  of  a  number  of  spherical  balls  in  a 
cast-iron  case,  of  the  usual  shape  of  a  projectile,  and  has  a  burst- 
ing-charge in  either  the  point  or  the  base  to  scatter  these  balls. 
Canister  is  in  a  cylindrical  case  and  has  no  bursting-charge. 
Shrapnel  has  a  point  combination  fuse  and  is  thus  readily  distin- 
guished from  all  other  projectiles.  (See  Fig.  43.) 

Q.  What  is  the  difference  between  cored  shot  and  shell? 

A.  Cored  shot  have  hollowed  centers,  as  also  have  shell,  but 
in  the  latter  the  hollow  is  much  larger.  Owing  to  the  recent 
manufacture  of  a  suitable  bursting-charge,  cored  shot  can  be 
filled  with  it  and  used  the  same  as  shell. 

Q.  What  is  the  general  color  of  the  main  body  of  all  projectiles  ? 

A.  Black. 

Q.  How  is  the  kind  of  metal  of  which  it  is  composed  marked  ? 

A.  By  a  painted  band  around  the  center,  half-caliber  wide. 

Q.  How  is  the  degree  of  armor-piercing  capacity  marked? 

A.  By  a  greater  or  lesser  portion  of  the  head  being  painted 
with  the  color  representing  the  metal  of  the  projectile. 

Q.  How  is  the  interior  bursting-charge  marked? 

A.  By  a  distinct  color  around  the  base  below  the  rotating- 
band. 

Q.  Give  the  colors  for  the  following  metals: 

1.  Forged  steel.  A.  i.  Blue-gray. 

2.  Cast  steel.  2.  Brownish  gray. 

3.  Cast  iron.  3.  Olive-green. 

4.  Chilled  iron.  4.  Light  olive-green. 

Q.  Give  the  colors  for  the  following  bursting-charges: 

1.  Gunpowder.  A.  i.  Bright  red. 

2.  Maximite.  2.  Brown. 

3.  Explosive  D.  3.  Yellow. 

Q.  How  are  the  interiors  of  shells  coated  ? 


84 


THE  GUNNER'S  EXAMINER. 


NOMENCLATURE   AND    GENERAL   DESCRIPTION. 


Rotating 
Band 


PROJECTILES. 

Bourrelet 


SOLID  SHOT  CAST  IRON. 


Point 


Cap 


SHELL. 

^Rotating  Band 


86  THE  GUNNER'S  EXAMINER. 

A.  With  a  special  varnish  furnished  by  the  Ordnance  Depart* 
ment. 

Q.  How  are  canister  painted  ? 

A.  Black  all  over. 

Q.  How  are  shrapnel  painted  ? 

A.  The  whole  body  black,  with  a  band  of  bright  red  on  the 
head  below  the  fuse  to  indicate  front  charge,  or  on  the  cylindrical 
portion  of  the  body  in  rear  of  the  copper  band  to  indicate  base 
charge,  depending  on  which  class — base  or  front  charge — it  is. 

Q.  How  are  shrapnel  distinguished  from  shell? 

A.  By  the  combination  point  fuse,  which  is  always  used  with 
shrapnel. 

Q.  What  is  meant  by  fixed  ammunition? 

A.  That  in  which  the  powder-charge  and  projectile  are  fixed; 
as  examples,  the  ammunition  for  small-arm  pieces  and  that  for 
the  6-pdr.  R.F.  gun  (which  is  made  in  the  same  way,  only  of  a 
larger  size),  the  powder  being  contained  in  a  brass  case,  the  projectile 
being  fastened  to  the  end  of  the  brass  case  and  a  percussion- 
primer  or  cap  being  in  the  base  of  the  same.  (See  Fig.  43.) 

Q.  Name  the  principal  parts  of  a  projectile. 

A.  The  main  body,  the  head,  the  bourrelet,  the  point,  the  base, 
and  the  rotating- band.  (See  Fig.  43.) 

Q.  In  what  kinds  of  projectiles  are  fuses  used? 

A.  Shell,  cored  shot,  and  shrapnel. 

Q.  What  is  the  rotating-band  made  of? 

A.  Copper. 

Note. — Recent  experiments  have  shown  the  superiority  of  a 
wider  and  heavier  band.  This  new  band  will  in  all  probability 
soon  be  adopted. 

Q.  Give  some  instructions  for  filling  shell. 

A.  Unscrew  and  remove  the  plug  from  the  shell.  Place  the 
filling-rod  in  the  bag  and  fold  the  latter  round  the  rod;  insert  it 
through  the  plug-hole,  taking  care  not  to  force  the  end  of  the  rod 
through  the  bottom  of  the  bag;  carefully  push  in  the  bag  until 
the  neck  only  is  in  the  plug-hole,  a  portion  being  kept  outside,  as 


NOMENCLATURE  AND   GENERAL   DESCRIPTION.  8? 

the  whole  bag  must  not  be  allowed  to  slip  irto  the  shell  during 
the  operation  of  filling;  then  withdraw  the  rod  and  insert  the 
funnel  into  the  neck  of  the  bag,  pressing  the  funnel  well  down 
into  the  plug-hole;  pass  the  filling-rod  through  the  funnel  and 
gradually  pour  in  a  small  quantity  of  the  powder  (say  about  half 
the  charge);  take  out  the  funnel  and  rod,  lift  up  the  bag  and  jerk 
it,  so  as  to  "set"  the  powder  well  down  to  the  bottom  and  to  open 
the  bag;  then  reinsert  the  funnel  and  rod  as  before,  and  continue 
the  filling ;  choke  the  bag  and  cut  off  the  superfluous  choke.  The 
filling-rod  should  be  moved  up  and  down  while  pouring  in  the 
powder,  to  facilitate  its  passage  through  the  funnel,  the  powder  in 
the  shell  being  tamped  on  at  the  same  time.  The  use  of  a  large 
mallet  against  the  side  of  the  shell  (any  piece  of  wood  will  answer 
the  same  purpose)  will  materially  assist  in  getting  the  maximum 
amount  of  powder  into  the  shell. 

When  the  shell  is  quite  full  withdraw  the  funnel  and  filling- 
rod,  and  tie  the  neck  of  the  bag  with  two  hitches  of  twine  close  to 
the  top  of  the  plug-hole.  Cut  off  the  superfluous  choke,  and  push 
the  neck  of  the  bag  well  down  the  plug-hole  into  the  shell,  then 
screw  in  the  plug  as  required. 

Lead  rings  are  supplied  for  the  armor-piercing  shell.  The  ring 
is  hammered  into  the  recess  round  the  head  of  the  plug,  and  the 
superfluous  metal  removed. 

No  preparation  of  the  bag  by  pricking  or  otherwise  is 
necessary. 

Q.  Suppose  a  projectile  when  weighed  on  a  scale  conies  to 
1044  Ibs.  and  that  it  has  a  blue-gray  head  and  a  blue-gray  band 
around  its  center  of  gravity,  and  below  the  copper  band  it  is  painted 
yellow;  state  what  gun  it  is  for,  what  kind  of  a  projectile  it  is 
(whether  a  shell  or  solid  shot),  what  it  is  made  of,  and  if  a  shell, 
what  is  inside  of  it. 

A.  It  is  an  armor-piercing  shell  for  a  1 2-inch  gun;  it  is  made 
of  forged  steel,  and  is  filled  with  explosive  "D." 

Q.  What  are  shell  and  cored  shot  filled  with? 

A-  Maximite,  explosive  "D,"  and  rarely  gunpowder. 


88  THE   GUNNER'S  EXAMINER. 

Q.  Why  should  shell  always  be  coated  carefully  with  a  lacquer 
or  varnish  before  being  filled? 

A.  Because  some  of  the  explosives  now  used  to  fill  shell,  though 
perfectly  stable  and  harmless  in  themselves,  become  very  sensitive 
explosives  when  exposed  to  steel  or  iron.  The  slightest  friction 
will  sometimes  detonate  them. 

Q.  Why  is  red  lead  or  white  lead  prohibited  on  fuse- threads  ? 

A.  Because,  as  with  iron,  some  shell-fillers  change  into  ex- 
tremely sensitive  explosives  on  contact  with  lead. 

Q.  Why  should  all  fixed  ammunition  and  primers  be  stored 
separately  from  magazines  containing  powder? 

A.  Because  they  are  liable  to  explode  by  dropping  or  break- 
ing, etc.,  and  the  shock  of  one  primer  or  charge  exploding  might 
explode  the  whole  magazine. 

Q.  Should  rubber  shoes  be  worn  in  magazines  ? 
•   A.  Yes. 

Q.  Why? 

A.  Because  there  are  always  priming-charges  of  black  powder 
in  every  section  of  smokeless  powder,  and  powder-dust  from  these 
might  fill  the  air  when  opening  cases,  and  a  spark  from  a  nail 
in  a  shoe  on  the  concrete  floor  would  ignite  it.  There  is  also  a 
remote  chance  of  the  vapor  of  ether  from  the  new  smokeless 
powder  exploding  when  in  combination  with  the  air. 

Rubber  matting  on  magazine  floors  would  be  best. 

(C)    CORDAGE,  BLOCKS,  TACKLE,  GINS,  SHEARS,  ETC. 

Q.  Define  yarn,  strands,  jaws  of  rope,  short-  and  long-jawed 
rope,  guys,  spun-yarn,  marlin,  standing  rigging,  running  rigging, 
and  a  bight. 

A.  Yarn  are  called  threads  of  hemp  or  other  fibrous  material 
which  compose  a  rope. 

Strand  is  a  number  of  yarns  twisted  together. 

Jaws  of  rope  are  the  interstices  between  the  strands  of  rope. 

Short- jawed  rope  is  a  rope  tightly  laid  up  together. 

Long- jawed  rope  is  a  rope  loosely  laid  up  together. 


NOMENCLATURE  AND   GENERAL   DESCRIPTION.  89 

Guys  are  stationary  ropes  to  hold  spars,  such  as  pry-pole?, 
shears,  etc.,  from  falling. 

Spun-yarn  is  made  by  twisting  together  very  loosely  two  or 
more  well-tarred  yarns.  It  is  used  for  serving,  seizings,  stops, 
etc.,  and  is  very  pliable. 

Marlin  is  also  made  of  tarred  yarns,  but  is  tightly  twisted  and 
is  much  harder  and  smoother  than  spun-yarn. 

The  bight  of  a  rope  is  any  part  not  an  end. 

A  bight  of  a  rope  is  formed  by  bending  or  doubling  the  rope 
so  as  to  form  a  loop. 

Standing  rigging  are  those  ropes  which  are  stationary. 

Running  rigging  are  those  which  run  through  blocks  or  pul- 
leys. (See  Figs.  45  and  46.) 

Q.  Explain  the  difference  between  hawser-laid  rope  and 
cable-laid  rope. 

A.  Cable-laid  rope  is  composed  of  nine  strands,  and  is  made 
by  first  laying  up  three  ropes  of  three  strands  each  with  the  sun, 
and  then  laying  the  three  ropes  together  into  one,  against  the 
sun.  Hawser-laid  rope  must  be  coiled  with  the  sun.  Hawser- 
laid  rope  is  a  right-handed  sope,  and  cable-laid  is  therefore  left- 
handed.  (See  Fig.  44.) 

Q.  How  is  the  size  of  the  rope  denoted? 

A.  The  size  of  the  rope  is  always  denoted  in  inches  and 
fractions,  and  is  measured  on  the  circumference.  (See  Fig.  44.) 

Q.  (a)  How  do  you  worm  a  rope?     (b)  Why? 

A.  (a)  Worming  a  rope  is  filling  up  the  divisions  between  the 
strands  by  passing  spun-yarn  along  them,  (b)  This  is  to  render 
the  surface  smooth  for  parceling  and  serving.  (See  Fig.  44.) 

Q.  (a)  How  do  you  parcel  a  rope?     (b)  Why? 

A.  (a)  Parceling  rope  is  wrapping  narrow  strips  of  canvas 
about  it,  well  tarred,  put  on  with  the  lay  of  the  rope,  (b)  To 
secure  it  from  being  injured  by  rain-water  or  to  prevent  chafing 
or  cutting  of  a  rope  when  a  strain  is  brought  against  a  rough 
surface  or  sharp  edge.  (See  Fig.  44.) 

Q.  (a)  How  do  you  serve  a  rope ?     (b)  Why? 


QO  THE  GUNNER'S  EXAMINER. 

A.  (a)  Serving  is  the  laying  on  of  spun-yarn  or  other  small 
stuff  in  turns  around  the  rope  close  together,  and  hove  taut  by 


Short  Jawed  Rope.  (Hawser  Laid) 


Worming  Serving 


Parcelling 


Cable  Laid  Rope 

FIG.  44. 

the  use  of  a  serving-board  for  small  rope  and  mallet  for  large 
rope.  Small  ropes  are  sometimes  served  without  being  wormed, 
as  the  crevices  between  the  strands  are  not  large  enough  to  make 


NOMENCLATURE  AND   GENERAL  DESCRIPTION.  91 

the  surface  very  uneven.  But  a  large  rope  is  always  wormed 
and  parceled  before  being  served,  (b)  The  service  is  put  on 
against  the  lay  of  the  rope.  (See  Fig.  44.) 

Qc  (a)  How  do  you  whip  a  rope  ?     (b)  Why  ? 

A.  (a)  Whipping  is  securing  the  end  of  a  rope  with  twine. 
(b)  To  prevent  it  from  fraying  out.  (See  Fig.  44.) 

KNOTS  AND   HITCHES. 

Q.  Make  the  following  knots  and  give  the  use  of  each: 
A  square  knot,  a  bowline,  single  sheet-bend  (weaver's  knot), 
double  sheet-bend,  rolling  hitch,  round  turn  and  two  half-hitches, 
clove-hitch,  catspaW,  blackwall  hitch,  sheep-shank,  a  marlin- 
spike-hitch. 

A.  See  Fig.  45.  This  figure  illustrates  the  manner  of  making 
these  knots.  Their  uses  are  as  follows : 

Square  knot:  A  quick  knot  to  tie  two  ends  of  rope  together 
that  will  not  slip. 

Bowline :  To  form  a  temporary  eye  at  end  of  a  rope.  This 
knot  can  be  easily  made  and  remembered  by  making  a  marlin- 
spike-hitch  and  putting  the  loose  end  of  the  bowline  through  the 
loop  where  the  spike  would  go. 

Single  and  double  sheet-bend:  To  tie  two  ropes  together. 
These  knots  do  not  jam.  When  one  rope  is  smaller  than  the 
other  the  double  sheet-bend  is  always  used,  making  the  double 
turn  with  the  smaller  rope. 

Rolling  hitch :  For  shifting  the  fall  from  one  end  of  a  windlass 
to  the  other. 

Round  turn,  two  half-hitches,  and  clove-hitch :  These  are  very 
useful  in  securing  the  guys  of  a  gin  to  the  stakes,  etc. 

Catspaw :  To  apply  the  purchase  or  tackle  to  the  fall  of  another. 

Blackwall  hitch :  To  fasten  the  end  of  a  rope  to  a  hook  when 
there  is  a  steady  strain  on  rope. 

Marlinspike- hitch :  Very  useful  in  putting  on  lashings,  etc. 

Q.  What  is  a  strap  or  sling,  and  what  is  its  use  ? 

A.  A  strap  or  sling  is  formed  by  knotting  or  splicing  together  the 
ends  of  a  short  strand  of  rope.  It  is  used  for  hooking  tackles  into. 


THE   GUNNER'S  EXAMINER. 


FIG.  45. 


NOMENCLATURE  AND  GENERAL   DESCRIPTION  93 


FIG.  46. — SHORT  SPLICE. 


FIG.  47. — LONG  SPLICE. 


94 


THE   GUNNER'S  EXAMINER. 


EYE     SPLICE 


FIG.  48. 


NOMENCLATURE  AND   GENERAL  DESCRIPTION.  95 

SPLICES. 

Q.  What  is  a  splice  ? 

A.  Splicing  is  putting  the  ends  of  rope  together  by  opening 
the  strands  and  placing  them  one  into  the  other,  or  by  putting 
the  strands  of  the  rope  between  those  of  the  bight. 

Q.  How  is  an  eye- splice  made  ? 

A.  Unlay  the  end  of  the  rope  for  a  short  distance  and  lay  the 
three  strands  upon  the  standing  part,  so  as  to  form  an  eye.  Put 
the  first  end  through  the  strand  next  to  it.  Put  the  second  end 
over  the  strand  and  through  the  second,  and  then  put  the  remain- 
ing end  through  the  third  strand  on  the  other  side  of  the  rope. 
Taper  them  as  in  the  short  splice  by  dividing  the  strands  and 
sticking  them  again.  The  eye-splice  is  used  to  form  a  permanent 
loop  in  the  end  of  a  rope.  (See  Fig.  48.) 

Q.  How  do  you  make  a  short  splice  ? 

A.  Unlay  the  strands  for  a  convenient  length;  take  an  end 
in  each  hand,  place  them  one  within  the  other,  and  draw  them 
close.  Hold  the  end  of  one  rope  and  the  three  strands  from  the 
other  in  the  left  hand ;  if  the  rope  is  large,  stop  them  down  to  it 
with  a  rope  yarn.  Take  the  middle  strand,  which  is  free,  pass  it 
over  the  strand  which  is  first  next  to  it,  then  through  under  the 
second  and  out  between  the  second  and  third  from  it,  and  then 
haul  it  taut.  Pass  each  of  the  six  strands  in  the  same  manner, 
first  those  of  one  end  and  then  those  of  another.  The  same 
operation  may  be  repeated  with  each  strand,  passing  each  over 
the  third  strand  from  it,  under  the  fourth  and  through ;  or,  as  is 
more  usual,  after  the  ends  have  been  stuck  once  untwist  each 
strand,  divide  the  yarns,  pass  one  half  as  above  described,  and  cut 
off  the  other  half.  This  tapers  the  splice.  (See  Figs.  45  and  46.) 

Q.  How  do  you  make  a  long  splice  ? 

A.  Unlay  the  ends  of  two  ropes  to  a  distance  three  or  four 
times  greater  than  for  a  short  splice,  and  place  them  within 
one  another  as  for  a  short  splice.  Unlay  one  strand  for  a  con- 
siderable distance  and  fill  up  the  interval  which  it  leaves  with  the 


96  THE  GUNNER'S  EXAMINER. 

opposite  strand  from  the  other  rope.  Twist  the  ends  of  these 
two  together,  then  do  the  same  with  two  more  strands.  The 
two  remaining  strands  are  twisted  together  in  the  place  where 
they  were  first  crossed.  Open  the  two  last-named  strands, 
divide  in  two,  take  an  overhand  knot  with  the  opposite  halves, 
and  lead  the  ends  over  the  next  strand  and  through  the  second 
as  the  whole  strands  were  passed  for  the  short  splice.  Cut  off 
the  other  two  halves.  Do  the  same  with  the  others  that  are 
placed  together,  dividing,  knotting,  and  passing  them  in  the  same 
manner.  Before  cutting  off  any  of  the  half -strands,  the  rope 
should  be  well  gotten  upon  a  stretch.  Sometimes  the  whole 
strands  are  knotted,  then  divided,  and  the  half-strands  passed 
as  above  described.  This  splice  does  not  increase  the  diameter 
of  the  rope,  and  it  is  used  for  splicing  a  fall  or  other  rope  that 
runs  through  blocks.  (See  Fig.  45.) 

RIGGING-TACKLES. 

Q.  What  is  a  tackle? 

A.  A  tackle  is  a  purchase  formed  by  reeving  a  rope  through 
one  or  more  blocks  for  the  purpose  of  hoisting  or  pulling. 

Q.  Name  the  parts  of  a  block. 

A.  The  shell,  sheave,  pin,  and  strap.     (See  Fig.  49.) 

Q.  Describe  the  following  blocks:  Single,  double,  treble, 
snatch,  and  tail. 

A.  Single  blocks  have  one  sheave;  double,  two;  treble,  three. 
A  tail-block  is  a  single  block  strapped  with  an  eye-splice  and 
having  a  long  end  by  which  to  make  the  block  fast  temporarily. 
A  snatch- block  is  a  single  block  having  a  notch  in  one  cheek  to 
receive  the  bight  of  a  fall.  (See  Fig.  49.) 

Q.  What  are  the  standing  parts,  the  running  parts,  and  the 
fall? 

A.  The  standing  parts  are  between  the  fasts  and  sheaves,  the 
running  parts  between  the  sheaves,  and  the  fall  the  part  held  in 
hauling. 

Q.  Describe  the  whip. 


NOMENCLATURE  AND   GENERAL  DESCRIPTION. 


97 


A.  A  rope  through  a  single  block.     (See  Fig.  49.) 
Q.  What  is  the  power  gained  if  the  block  be  fixed? 


Whip  upon  Whip  (/Gun  Tackla 


Luff  upon  Luff 

FIG.  49. 
'  A.  None. 
Q.  Describe  the  whip  upon  whip. 


Marlin  Spike  Hitch 


98  THE  GUNNER'S  EXAMINER. 

A.  The  block  of  one  whip  is  made  fast  to  the  fall  of  another. 
(See  Fig.  49-) 

Q.  What  is  the  power  gained  ? 

A.  Double  if  only  one  block  moves.     Quadruple  if  both  move. 

Q.  Describe  the  gun-tackle. 

A.  A  rope  passed  through  two  single  blocks  and  made  fast  to 
one.  (See  Fig.  49.) 

Q.  What  is  the  power  gained  ? 

A.  Double.     Treble  if  block  to  which  rope  is  made  fast  moves. 

Q.  Describe  the  luff-tackle. 

A.  A  rope  hove  through  a  single  and  a  double  block  and  made 
fast  to  the  single  block.  (See  Fig.  49.) 

Q.  What  is  the  power  gained  ? 

A.  Treble.     Quadruple  if  the  block  moves. 

Q.  What  is  a  luff  upon  luff? 

A.  A  luff -tackle  on  the  fall  of  another  luff.     (See  Fig.  49.) 

Q.  Describe  the  single  Burton. 

A.  A  rope  rove  through  two  single  blocks,  with  a  hook  in  the 
bight  of  the  running  part. 

Q.  What  is  the  power  gained  ? 

A.  Treble.     Quadruple  if  both  blocks  move. 

Q.  How  is  power  determined  when  one  tackle  is  applied  to 
the  fall  of  another  ? 

A.  It  is  equal  to  the  product  of  their  respective  powers. 

Q.  What  is  mousing,  and  what  is  its  purpose  ? 

A.  A  seizing  around  a  hook  to  prevent  it  from  spreading  or 
unhooking.  (See  Fig.  49.) 

Q.  What  is  a  bight  of  a  hook  ? 

A.  The  middle  of  a  bend  of  a  hook.     (See  Fig.  49.) 


GINS. 

Q.  Name  the  different  parts  of  a  garrison-gin. 
A.  It  is  composed  of  three  poles  (two  legs  and  a  pry-pole), 
braces,  a  bolt,  clevis,  windlass,  two  handspikes,  three  shoes,  and 


NOMENCLATURE  AND   GENERAL   DESCRIPTION. 


99 


a  hoisting-apparatus  consisting  of  two  blocks  (one  triple  and  one 
double).     (See  Fig.  50.) 

Q.  How  much  can  be  safely  lifted  with  it? 

A.  17,000  Ibs. 

THE  GARRISON  GIN. 


Block 
(Quadruple) 


Left  Leg 


Right  Leg' 


FlG.  50. 

Q.  How  can  the  upper  block  be  placed  in        |^ — Hand  Spike 
position  after  the  gin  has  been  raised  ? 

A.  By  rigging  a  truce  rope  through  the  clevis  and  hoisting  it  up. 
Q.  Explain  briefly  how  you  would  raise  a  gin. 

SHEARS. 

Q.  Describe  the  parts  of  the  shears. 

A.  Two  spars  lashed  together  at  one  point,  forming  an  in- 
verted V,  the  ends  being  called  heels,  the  upper  end  the  head, 
and  the  part  where  the  lashing  is  applied  is  called  the  cross. 

The  equipment  consists  of  the  following  stores:  Two  double 
blocks,  two  single  blocks  for  gin-tackles;  one  double  block,  one 


100 


THE  GUNNER'S  EXAMINER. 


treble  block,  and  one  snatch-block  for  the  main-tackle  fall; 
guys,  head-lashing,  heel-lashing,  and  straps  for  main  tackle; 
snatch-block,  holdfasts,  and  some  spun-yarn  for  -mousing,  etc.; 
two  cleats  for  heels  to  prevent  lashing  from  slipping;  stakes  for 
holdfasts  for  guys  and  heel-posts;  two  shoes  for  heels.  (See  Fig. 

44-) 

Q.  What  are  shears  used  for  ? 

A.  For  lifting  heavy  weights  over  the  face  of  a  wall  or  cliff, 
or  in  other  situations  where  the  gin  could  not  be  used  for  want 
of  a  footing  for  the  pry-pole. 

Q.  How  do  you  pass  a  shear-lashing  ? 

A.  Middle  the  lashing  and  take  a  turn  around  both  legs 
at  the  cross;  pass  one  end  up  and  the  other  down,  around 
and  over  the  cross,  until  half  of  the  lash  is  expended;, 
then  ride  both  ends  back  again  on  their  own  parts  and  knot 
them  in  the  middle;  frap  the  first  and  riding  turns  together 
on  each  side  with  sennit.  This  will  be  useful  in  rigging 
shears  for  hoisting  guns  when  a  gin  is  not  available.  Any  two- 
spars  that  will  support  the  weight  can  be  used.  (See  Fig.  51.) 


Shear  Lashing 
Figuce  8  Form 


FIG.  51. 

Lay  the  middle  of  the  back  guy  in  the  cross;  bring  the  left- 
hand  end  up  around  the  right  leg  and  over  the  head  of  the  left 
leg;  then  carry  the  right-hand  end  around  under  both  legs;  let 


NOMENCLATURE  AND  GENERAL  DESCRIPTION.  101 

it  cross  over  the  left-hand  end,  and  seize  them  together  with 
spun-yarn. 

Q.  How  is  a  square  lashing  made? 

A.  Place  two  spars  at  right  angles  and  pass  several  turns 
around  two  opposite  angles  of  the  X,  then  several  turns  around 
the  other  two  opposite  angles.  Continue  this  until  the  spars  are 
firmly  lashed  and  will  not  move;  tie  the  ends.  This  lashing  is 
used  to  make  two  spars  rigid  and  at  right  angles  to  each  other. 

Q.  How  are  shears  rigged  and  raised? 

A.  Lay  the  heads  of  the  spars  on  a  trestle  about  three  feet 
high,  the  right  leg  above  the  left,  so  that  they  cross  at  about 
twice  their  thickness  from  the  ends,  with  the  heels  in  their  proper 
positions. 

Make  a  bowline-knot  in  the  end  of  the  fore  guy  and  slip  it  over 
the  head  of  both  legs. 

Lay  the  middle  of  the  main-tackle  strap  under  the  cross  above 
the  fore  guy;  bring  the  ends  up  over  the  cross;  hook  the  upper 
block  to  them  under  the  cross  below  the  fore  guy  and  mouse  it, 
taking  care  that  the  splice  comes  in  the  middle  of  the  strap  and 
that  the  fall  leads  to  the  rear. 

Drive  the  heel-posts  on  each  side  the  heels  about  a  foot  toward 
the  head  and  one  foot  outside;  lay  the  shoes  under  the  heels; 
make  a  timber-hitch  around  the  inner  posts  with  the  heel-lash- 
ings; pass  three  turns  over  the  legs  below  the  cleats,  and  hitch 
the  lashings  to  the  outer  posts.  Drive  four  holdfasts  for  each 
back  guy,  as  follows:  two  on  each  side  the  line  of  the  legs  pro- 
longed, three  feet  apart,  and  two  six  feet  in  the  rear  of  these. 

Lay  the  ends  of  the  guy-straps  over  the  front  stakes;  connect 
each  pir  of  front  and  rear  stakes  with  a  strap  twisted  up  taut 
to  insure  the  strain  being  distributed  properly. 

Drive  two  holdfasts  for  the  fore  guy,  one  in  the  rear  of  the 
other,  in  the  prolongation  of  the  axis  of  the  shears. 

Hook  the  upper  blocks  of  the  guy-tackles  to  a  bowline  in  the 
end  of  the  guys,  and  the  single  block  to  the  guy-strap,  and  mouse 
them  all. 


102  THE  GUNNER'S  EXAMINER. 

Ordinarily  the  fore  guy  can  be  worked  without  a  tackle,  belay- 
ing it  over  the  holdfasts,  first  taking  a  round  turn  over  the  one 
next  the  shears.  If  not  too  heavy,  the  shears  may  be  raised  by 
lifting  the  head  and  hauling  on  the  guy-tackles,  slacking  the 
heel-lashings  as  required,  and  tending  the  fore  guy  carefully  to 
prevent  the  shears  falling  over  toward  the  rear. 

Q.  How  are  shears  held  in  position  after  being  raised? 

A.  By  guys  and  holdfasts. 

Q.  What  is  the  inclination  or  rake  of  the  shears  with  the  level 
of  the  ground  ? 

A.  About  20  degrees. 

Q.  How  can  a  change  in  the  direction  of  the  fall  of  the  tackle 
be  made  to  lead  to  a  capstan? 

A.  Hook  the  snatch-block  to  a  strap  placed  below  the  cleat  on 
either,  and  pass  the  fall  through  it  to  the  capstan. 

HYDRAULIC  JACKS. 

Q.  For  what  is  the  hydraulic  jack  used? 

A.  For  lifting  very  heavy  weights. 

Q.  What  is  the  difference  between  the  base  jack  and  the  hori- 
zontal jack  ? 

A.  The  former  has  the  lever,  socket,  etc.,  at  the  top  of  the 
jack,  while  the  latter  has  the  working  parts  near  the  base.  (See 
Figs.  52  and  53.) 

Q.  What  is  the  principle  involved  in  hydraulic  jacks? 

A.  A  pump  operated  by  hand  forces  a  small  amount  of  alcohol 
through  a  narrow  valve  into  a  recess  containing  a  ram  or  large 
piston-rod.  As  the  alcohol  is  forced  into  this  recess  it  raises  the 
ram :  thus  a  weight  upon  the  ram-head  is  raised.  The  alcohol  is 
prevented  from  running  back  into  the  main  reservoir  by  valves 
similar  to  those  on  all  pumps. 

Q.  What  is  the  best  liquid  to  use  in  filling  jacks  ? 

A.  For  the  base  jack  one  part  alcohol,  two  parts  water;  for 
the  horizontal  jack  one  part  alcohol,  one  part  water,  and  for 
both  add  a  tablespoonful  of  sperm-oil. 


NOMENCLATURE  AND  GENERAL  DESCRIPTION. 


103 


Q.  Name  the  principal  parts  of  a  jack. 

A.  The    cylinder,    ram,    reservoir,    socket,    knuckle,    piston, 
BASE    JACK. 


Piston  Packing 

Piston  Packing  Ring 

Piston  Bonnet 


Bottom  Packing 
Bottom  Packing  Rin 


Pump 

Piston  Valve 
Back  Flow  Passages 
Packing 
Pump  Valva 
Pump  Plug 
am  Packing 
eking  Ringa 
live  Spring 
mp  Bonnet 


FIG.  52. 

piston-valve,  pump,  pump-valve,  lowering-valve,  packing-springs, 
etc.  (See  Figs.  52  and  53.) 

Q.  How  can  a  weight  be  raised  when  the  jack  will  not  go  under 
the  weight? 

A.  By  the  use  of  a  movable  claw. 


104 


THE  GUNNERS  EXAMINER. 


Q.  Give  some  general  instructions  for  the  care  and  use  of  the  jack. 
A.  Never  fill  with  water,  kerosene,  or  wood-alcohol.     Keep 
the  ram  down  when  not  in  use.     If  the  valve  sticks  on  its  seat, 
HORIZONTAL  JACK 


Valve 


Reservoi 


Lowering  Valve 

(Dotted) 

Ram  Packing 

Ram  Packing  Ring 

Ram  Packing 

Ring  Nut 

Bottom  Packing 
Bottom  Packing  Ring 

Pump  Small  Nut — ' 


Socket 
Knuckle 


Piston 
Pump  Nut 
Piston  Valve 
•  Piston  Packing 
•Piston  Packing 
Ring 

Piston  Valve 
Bonnet 

Pump 

Pump  Valve 
P.V.  Spring 
P.V.  Bonnet 

strike  the  lever  a  few  sharp  blows  up  and  down,  thus  jarring  the 
valve.  Use  the  alcohol  supplied  by  the  Ord.  Dept. 

Base  jacks  should  never  be  used  so  that  the  head  is  lower  than 
the  foot.  A  jack  should  be  used  once  a  week  to  keep  the  packing 
in  order. 

Never  apply  more  than  150  pounds  to  the  lever:  this  equals 
about  the  weight  of  the  average  man. 


FIG.  53. 


NOMENCLATURE  AND  GENERAL  DESCRIPTION.  Iog 

THE   U.  S.  MAGAZINE   RIFLE. 

Q.  Point  out  the  following  parts  of  the  Model  1903,  Cal.  30 
magazine  rifle: 

Barrel,  Guard,  Firing  Pin, 

Stock,  Cut  Off,  Cocking  Piece, 

Butt,  Sleeve,  Main  Spring, 

Bayonet,  Sleeve  Lock,  Follower, 

Bolt,  Stacking  Swivel,  Hand  Guard, 

Trigger,  Extractor,  Drift  Slide, 

Sights,  Ejector,  Striker. 
Windage  Screw, 

A.  See  Figs.  54,  55. 

Q.  Point  out  the  following  parts  of  the  Ball  Cartridge: 

Case,        Primer,        Charge,        Bullet. 

A.  See  Fig.  56. 

Q.  What  is  meant  by  the  term  caliber  ? 

A.  It  is  the  diameter  of  the  bore  in  inches. 

Q.  What  is  the  trigger  pull  ? 

A.  Three  to  four  and  one  half  pounds. 

Q.  What  is  the  weight  of  the  rifle  and  bayonet? 

A.  9.69  pounds. 

Q.  What  is  the  maximum  ordinate  at  1000  yards? 

A.  21.26  feet. 

Q.  What  is  the  weight  of  the  bullet  ? 

A.  220  grains. 

Q.  What  is  the  weight  of  charge  of  powder? 

A.  42  grains  of  smokeless  powder. 

Q.  What  is  the  muzzle  velocity  ? 

A.    2200  f.  S. 

Q.  How  many  cartridges  will  the  magazine  hold  ? 

A.  Five. 

Q.  How  is  the  rifle  cleaned  ? 


io8 


THE  GUNNER'S  EXAMINER. 


A.  To  clean  the  barrel,  insert  in  the  chamber  a  cartridge  shell, 
the  front  end  of  which  has  been  filled  with  a  wooden  plug,  and 
close  the  bolt.  Clean  the  bore  with  a  rag  saturated  with  soda 
water,  or  if  this  is  not  obtainable,  with  water.  Wipe  dry  with 
clean  rags.  Remove  the  bolt  and  the  cartridge  shell,  clean  and 
dry  the  chamber  from  the  rear.  Thoroughly  oil  the  chamber  and 
the  bore  with  a  light  coat  of  cosmoline  oil.  The  stock  and  hand 
guard  may  be  coated  with  raw  linseed  oil  and  polished  by  rubbing 
with  the  hand. 

Q.  When  is  the  multiball  cartridge  used  ? 

A.  In  cases  where  the  great  range  of  the  service  bullet  would 
endanger  persons  or  property  at  a  considerable  distance  from  firing. 

Q.  Of  what  is  a  multiball  cartridge  composed  ? 

A.  The  service  case  charged  with  34  grains  of  smokeless  pow- 
der and  two  round  balls. 

Q.  What  is  the  effective  range  of  the  multiball  cartridge  ? 

A.  200  yds.,  when  sights  must  be  set  for  350  yds.  At  100  yds. 
or  less  fire  point  blank. 

Q.  Illustrate  to  the  instructor  how  you  would  set  the  sight  for 
a  given  range,  using  both  open  and  peep  sights. 

Q.  To  shoot  to  the  right  (or  left),  which  way  would  you  move 
the  sight? 

NOMENCLATURE  . 

(For  Reference  Only.) 

COMPONENT  PARTS. 

(One  hundred  and  two  in  number.) 
Bayonet: 

Bayonet  Blade. 


Barrel: 

Barrel. 

Front  Sight  Stud. 

Front  Sight  Stud- 
Pin. 

Rear  Sight  Base. 

Rear  Sight  Base  Pin. 

Rear  Sight  Base. 
Spline. 


Assem- 
bled. 


Bayonet  Guard. 
Bayonet  Guard  Riv- 
ets (2). 
Bayonet  Catch. 
Bayonet  Scabbard  Catch. 
Bayonet  Spring. 
Bayonet  Spring  Cup. 


Assem- 
bled. 


NOMENCLATURE  AND  GENERAL  DESCRIPTION. 


109 


,,    , 


bled. 


1  Assem- 
J    bled. 

1  Assem- 
[   bled. 


Bayonet: 

Bayonet  Grip,  right. 

Bayonet  Grip  Screw 
Washer. 

Bayonet  Grip,  left. 

Bayonet  Grip  Screw 
Nut. 

Bayonet  Grip  Screw. 
Bolt: 

Bolt. 

Extractor  Collar. 
Bolt  Stop: 

Bolt  Stop  Pin. 

Bolt  Stop  Spring. 
Butt-plate: 

Butt-plate. 

Butt-plate  Cap. 

Butt-plate  Cap  Pin. 

Butt-plate  Cap  Spring. 

Butt-plate  Cap  Spring  Screw. 

Butt-plate  Screw,  large. 

Butt-plate  Screw,  small. 

Butt  Swivel: 
Butt  Swivel. 
Butt  Swivel  Pin. 
Butt  Swivel  Plate. 

Butt  Swivel  Plate  Screws  (2). 
Cut-off: 

Cut-off. 

Cut-off  Spindle. 

Cut-off  Spindle  Screw. 

Cut-off  Spring. 

Cut-off  Spring  Spindle. 
Ejector. 
Ejector  Pin. 


Assem- 
bled. 


Extractor. 
Firing  Pin: 

Cocking  Piece.          1  Assem- 
Firing  Pin  Rod.        J    bled. 
Firing  Pin  Sleeve. 
Follower, 
ront  Sight: 
Front  Sight. 
Front  Sight  Pin. 
Front  Sight  Movable  Stud. 
Front  Sight  Movable  Stud 

Screw. 
Floor  Plate. 
Guard : 
Guard. 

Floor  Plate  Catch. 
Floor  Plate  Catch  Pin. 
Floor  Plate  Catch  Spring. 
Guard  Screw,  front. 
Guard  Screw,  rear. 
Guard  Screw  Bushing. 
Hand  Guard. 
Lower  Band. 
Lower  Band  Spring. 
Lower  Band  Swivel. 
Lower  Band  Swivel  Screw. 
Magazine  Spring. 
Mainspring. 
Rear  Sight: 
Base  Spring. 

Drift  Slide.  jAssem- 

Drift  Slide  Pin.  J   bled. 

Joint  Pin. 
Leaf. 
>  Movable  Base. 


no 


THE  GUNNER'S  EXAMINER. 


Rear  Sight: 
Slide. 

Slide  Binding  Screw. 
Slide  Binding  Screw  Pin. 
Slide  Cap. 
Slide  Cap  Screw. 
Windage  Screw. 
Windage  Screw  Collar. 
Windage  Screw  Knob. 
Windage  Screw  Knob  Pin. 
Windage  Screw  Spring. 
Receiver. 
Safety-lock: 
Safety-lock  Spindle. 
Safety-lock  Spring. 
Safety-lock    Spring      Assem- 
Spindle.  f    bled. 

Safety-lock  Thumb- 
piece. 


Sear. 

Sear  Joint  Pin. 
Sear  Spring. 
Sleeve : 

Sleeve. 

Sleeve  Lock. 

Sleeve  Lock  Pin. 

Sleeve  Lock  Spring. 
Stacking  Swivel. 
Stacking  Swivel  Screw. 
Stock. 
Striker. 
Trigger. 
Trigger  Pin. 
Upper  Band. 
Upper  Band  Screw. 


APPENDAGES. 


Cleaning  Rod. 
Front  Sight  Cover. 
Oiler  and  Thong  Case: 

Oiler  and  Thong  Case,  Collar, 

and  Partition. 
Thong  Case  Cap  and  Leather 

Pad. 

Oiler  Cap  and  Dropper. 
Oiler  Cap  Washer. 


Screw-driver. 
Thong  and  Bush: 

Brush. 

Thong  Cord. 

Thong  Tip. 

Thong  Weight. 


CHAPTER    II. 


EXAMINATION    OF   FIRST-CLASS    GUNNERS. 

(a)    THE   AZIMUTH   INSTRUMENT   AND    DEFINITIONS. 

Q.  What  is  an  angle  ? 

A.  An  angle  is  the  divergence  of  two  intersecting  lines. 
In  Fig.  57   the  two  intersecting  lines  SA  and  XA  form  the 
angle  5^4  X,  and  when  measured  on  the  circle  with  A  as  the  center 


-270° 


FIG.  57. 

it  is  found  to  be  equal  to  8o°.45  (eighty  and  forty-five  hundredths 
degrees). 

Q.  Into  how  many  degrees  is  a  circle  divided? 

A.  360. 

-Q.  How  is  each  degree  divided  in  the  U.  S.  Artillery  service? 

A.  Each  degree  is  divided  into  one  hundred  equal  parts. 


112  THE  GUNNER'S  EXAMINER. 

Q.  Define  a  circle. 

A.  A  circle  is  a  plane  figure  bounded  by  a  curve,  every  point 
of  which  is  equally  distant  from  a  point  within  called  the  center. 
Fig.  57  represents  a  circle  with  A  as  the  center. 

Q.  What  is  the  vertex  of  an  angle? 

A.  The  point  where  the  two  intersecting  lines  cross.  As  in 
Fig.  57,  A  is  the  vertex  of  the  angle  5^4 X. 

Q.  Define  an  azimuth  angle. 

A.  It  is  a  horizontal  angle  measured  from  zero  degrees  at  the 
south  in  a  clockwise  direction. 

Q.  What  is  meant  by  a  horizontal  angle? 

A.  One  whose  intersecting  lines  or  sides  are  parallel  with  the 
level  of  water  at  that  point. 

Q.  What  is  a  vertical  angle? 

A.  One  whose  sides  lie  in  a  plane  of  a  plummet. 

Q.  Can  an  azimuth  angle  be  greater  than  90°? 

A.  Yes.  See  Fig.  51.  SAT  =  azimuth  of  target  (less  than 
90°);  5^4  T'=  azimuth  of  target  (greater  than  90°,  but  less  than 
1 80°);  SA  T"  =  azimuth  of  target  (greater  than  270°).  (All  these 
azimuth  angles  are  read  in  a  clockwise  direction  from  zero  at  the 
south.) 

Q.  When  is  a  gun  or  an  instrument  said  to  be  set  in  azimuth? 

A.  When  it  reads  zero  and  points  south. 

Q.  What  is  an  azimuth-instrument? 

A.  A  device  for  measuring  horizontal  angles. 

Q.  Point  out  the  following  parts  of  the  instrument: 

1.  Telescope-tube.  17.  Prism-cap.  32.  Disk-crank. 

2.  Telescope-trunnion.        18.  Cross- wire   adjusting-    33.  Worm  adjusting-screw. 
Trunnion  clamp-screws  screw.  34.  Reading-opening. 


4- 

Focusing-knob. 

19. 

Instrument-base. 

35- 

Azimuth-clamp,  [screw. 

5- 

Sunshade. 

20. 

Leveling-screws. 

36. 

Azimuth  slow-motion 

6. 

Dew-cap. 

21. 

Spindle-head. 

37- 

Telescope-yoke. 

7- 

Objective-cell. 

22. 

Worm-gear. 

38. 

Yoke-caps. 

8. 

Objective. 

23- 

Graduated  circle. 

39- 

Levels. 

9- 

Eyepiece-adapter. 

24. 

Worm-screw. 

40. 

Level-holders. 

10 

Eyepiece. 

25- 

Worm-box. 

41. 

Level-adjusting  screws. 

ii. 

Eye-lens. 

26. 

Worm-box  spring. 

42. 

Plumb-bob 

12. 

Field-lens. 

27. 

Worm-box  pivot. 

43- 

Plumb-bob  chain. 

13- 

Cross-  wire  holders. 

28. 

Worm-box  adjusting- 

44. 

Tripod-head. 

14. 

Cross-wire. 

screws,           [crank. 

45- 

Tripod-cap. 

IS- 

Brashear   -   Hastings 

29. 

Worm-box    eccentric- 

46. 

Tripod-thumbscrew. 

erecting-prism. 

30- 

Index-disk. 

47- 

Tripod-legs. 

16. 

Prism-holder. 

31- 

Index-pointer. 

48. 

Pier-mounts. 

EXAMINATION  OF  FIRST-CLASS  GUNNERS.  113 

A.  See  Fig.  58. 

Q.  Describe  how  to  set  the  azimuth-instrument  up  for  use. 

A.  First:  Set  the  graduated  circle  and  index-disc  to  read  the 
known  azimuth  of  a  visible  object  and  clamp  (the  eccentric- 
crank  being  in  gear). 

Second:  Set  the  eyepiece  slightly  to  the  left  of  the  reading- 
opening  and  tighten  the  azimuth-clamp. 

Third :  Raise  the  whole  instrument  by  grasping  the  tripod,  and 
turn  it  so  that  the  telescope  points  approximately  in  the  direction 
of  the  visible  object  whose  azimuth  is  known,  being  careful  to  set 
the  plumb-bob  over  the  home  station  at  the  same  time  and  not 
destroy  the  setting  of  the  graduated  circle  and  index-disc. 

Fourth:  Level  the  instrument.  (This  is  done  by  loosening 
the  azimuth-clamp  and  setting  one  level  parallel  to  two  opposite 
leveling-screws,  then  turn  these  two  screws  either  both  inward 
toward  the  spindle-head  or  both  outward  until  the  bubble  comes 
in  the  middle.  Perform  the  like  operation  with  the  other  two 
leveling-screws  and  the  instrument  is  level.) 

Fifth:  Release  the  azimuth- clamp  and  set  the  telescope  as 
nearly  as  possible  on  the  object,  then  clamp  and  set  the  vertical 
cross-hair  exactly  by  turning  the  azimuth  slow-motion  screw. 
Verify  the  setting  of  the  index-disc  and  the  levels.  The  instru- 
ment is  now  set  in  azimuth.  Azimuth  instruments  for  mounting 
on  the  parapet  have  turned  on  their  levelling  screws  so  as  to 
bring  reading  opening  convenient  to  the  eye. 

Q.  How  is  the  azimuth  of  any  other  point  read  after  the 
instrument  is  set  up? 

A.  By  turning  the  index-disc  crank  until  the  vertical  hair  cuts 
the  object.  Read  the  even  degrees  on  the  graduated  circle,  and 
hundredths  of  a  degree  on  the  index-disc.  (In  order  to  make  a 
considerable  change  in  azimuth-reading,  much  time  is  saved  by 
releasing  the  eccentric-crank,  turning  the  telescope  approximately 
on  the  object,  throwing  the  eccentric-gear  again  and  reading 


TT4 


THE   GUNNER'S  EXAMINER. 


accurately  by  turning  the  index-disc  till  the  vertical  hair  cuts  the 
object.) 

Q.  Why  are  not  azimuth-circles  on  guns,  mortars,  etc.,  always 
graduated  so  that  their  zeros  will  point  south  ? 


Trunnion  Clamp  Sere 
Eye  Lens          Fj'eld  Lens 


,Yoke  Cap 

Telescope  Trunnion 

ocusing  Knob 


Azimuth  Slow 

Motion 

""Levelling  Screws 
-Instrument  Base 


Eye  Piece 


Eye  Piece  Adapt 

Crosswire  Holder  and 
Adjusting  Screws 


Worm  Adjusti 

Screw  Index  Disc 


Objective  and 
Objective  Cell 


Dew  Cap 


n  Clamp 

Azimuth  Clamp  Worm  Box  Eccentric 

Crank 


Worm  Box 
djusting  Screw 

orm  Box 


Tripod  Legs 


•Tripod  Head 

Worm  Bo 
Spring' 

Plumb  Bob 
Chain 


Index  Pointer 


Plumb  Bob 


\w 


Reading 
Opening 

orm  Gear 


FIG.  58. 

A.  If  this  were  always  done,  the  azimuth  indicator-plate  or 
subscale  would  have  to  be  directly  under  the  muzzle  of  the  gun — 
a  very  awkward  and  inconvenient  place.     These  azimuth  sub- 
scales  are  therefore  placed  on  the  side,  and  when  the  gun  or  mortar 
points  south  the  subscale  points  at  zero  on  the  azimuth-circle. 
Q.  Give  some  rules  for  caring  for  the  azimuth  instrument, 
A.  Never  allow  any  of  the  leveling-screws  to  become  so  tight 
that  they  cannot  be  easily  turned  by  hand.    When  setting  the 
instrument  up  over  a  concrete  floor  make  little  holes  in  the  con- 


EXAMINATION  OF  FIRST-CLASS  GUNNERS.  IZ5 

crete  for  the  points  of  the  tripod-legs  to  set  in.  Never  wipe  the 
lenses  with  anything  having  the  least  sign  of  dirt  or  grit  upon  it. 
A  perfectly  clean  chamois  is  always  best.  See  that  all  screws  are 
firmly  clamped  before  putting  the  instrument  away  in  the  wooden 
carrying-box.  In  removing  it  from  the  box,  pick  it  up  by  placing 
the  hands  underneath  the  worm-gear.  Never  clamp  the  instru- 
ment too  tightly  to  the  tripod-head.  After  the  instrument  is  once 
leveled  avoid  jarring  or  leaning  upon  it. 

Q.  In  case  the  azimuth-instrument  will  not  stay  level  after 
performing  the  usual  operation  of  leveling,  how  do  you  adjust  the 
levels? 

A.  Set  one  level  parallel  with  two  opposite  leveling-screws, 
and  bring  the  bubble  to  the  center  by  turning  these  two  screws 
either  both  inward  or  both  outward.  Reverse  the  telescope 
through  1 80°.  If  the  bubble  is  not  in  the  center,  this  level  is  out 
of  adjustment.  Now  correct  one  half  of  the  error  by  using  the 
small  steel  pin  on  the  little  adjusting-screws  on  the  levels,  and  the 
other  half  by  using  the  two  opposite  leveling-screws  referred  to 
above.  Now  turn  the  telescope  180°  again.  If  it  is  still  out 
of  level,  continue  the  above  method  of  correction  until,  on 
reversing  the  telescope,  no  change  in  motion  of  the  bubble  can 
be  observed. 

Q.  Give  a  rule  for  finding  the  least  count  of  a  vernier. 

A.  Divide  the  value  of  the  smallest  division  on  the  limb  or 
main  scale  by  the  number  of  divisions  there  are  on  the  vernier. 
The  result  is  equal  to  the  least  count  on  the  vernier. 

Q.  How  would  you  focus  the  telescope. 

A.  Focus  the  eyepiece  until  the  cross-wires  appear  rough. 

Then  turn  the  telescope  on  some  distant  object  and  focus  the 
objective  by  means  of  the  focusing-knob  until  the  intersection  of 
the  cross-wires  remains  on  the  same  point,  when  the  eye  is  moved 
up  and  down  and  to  right  and  left. 

Q.  Set  up  the  azimuth  instrument  over  a  given  point;  level, 
orient,  and  focus  it. 

(This  should  be  practiced  frequently.) 


n6  THE  GUNNER'S  EXAMINER. 

EXAMPLES. — I.  The  number  of  divisions  on  a  vernier  =  25. 
The  value  of  the  smallest  division  on  the  main  scale  =25  yards. 
What  is  the  least  reading  of  the  vernier? 

Ans.  25-^25=1  yard. 

II.  The  value  of  the  smallest  division  on  the  main  scale  of 
the  mercurial  barometer  =TV  of  an  inch.  The  number  of  divi- 
sions on  the  vernier  =  10.  What  is  the  least  count  of  the  vernier  ? 

Ans.  tV  -^  10  =TTRT  of  an  inch. 

Note. — The  following  scheme  for  accurately  counting  seconds 
has  been  found  valuable  to  gunners  who  have  no  stop-watches ;  it 
is  also  used  by  many  photographers  in  timing  pictures.  When 
ready  to  start  to  count  the  time  of  flight,  for  example,  trail  your 
gun  or  instrument  on  the  target,  stop  traversing,  and  count  to 
yourself :  One  one  thousand,  two  one  thousand,  three  one  thousand, 
four  one  thousand,  etc.,  until  finished,  saying  one  thousand  after 
each  number.  The  time  required  by  the  average  man  to  say  one 
one  thousand  or  eight  one  thousand  is  equal  to  one  second.  With 
but  little  practice  a  gunner  can  be  trained  to  count  as  high  as  20 
seconds  accurately.  In  such  cases  stop-watches  are  not  necessary.- 

(6)  THE   PLOTTING-ROOM. 

Q.  Point  out  or  describe  the  following  parts  of  the  Whistler- 
Hearn  plotting-board :  The  table,  the  azimuth-circle,  azimuth 
graduations  for  primary  and  secondary  stations,  base-line  arm, 
base-line  plate,  primary  station,  secondary  station,  primary  arm, 
secondary  arm,  directing-gun  arm,  directing-gun  azimuth-circle, 
base-line  verniers,  directing-gun  vernier,  base-line-arm  verniers, 
azimuth-indices  for  primary  and  secondary  stations,  auxiliary 
arm,  connecting- bar,  clamp  for  arm  index-clamp,  gun-arm  clamp, 
reading-opening  for  directing-gun  azimuth- circle,  index  for  gun 
azimuth-circle,  speed-scale  for  range,  speed- scale  for  azimuth 
or  azimuth-travel  devices,  range  correction-device,  azimuth  cor- 
rection-device, micrometer,  the  "targ,  tally  dials." 

A.  See  Figs.  59,  60,  61,  and  62.  These  figures  show  by  steps 
the  "evolution  of  the  Plotting  Board." 


EXAMINATION   OF  FIRST-CL4SS   GUNNERS. 
SIMPLE  PLOTTING-BOARD. 


117 


Water' 


FIG.  59. 
PLOTTING-BOARD  WITH  GUN-ARM. 


FIG.  60. 


n8 


THE   GUNNER'S  EXAMINER. 


Q.  Describe  how  to  obtain  the  range  of  a  target  from  the 
primary  or  secondary  station  when  the  azimuth-angles  from  the 
primary  and  secondary  stations  are  given  to  you. 

A.  First:  Set  the  auxiliary-arm  index  to  read  the  number  of 
even  degrees  the  target  is  from  the  secondary  station,  setting 
the  arm-clamp  in  the  V-shaped  notch  on  the  azimuth-circle  cor- 
responding to  that  number  of  degrees. 

THE  MODERN  PLOTTING-^OARD. 

^Connecting  Bar 


FIG.  61. 

Second:  Set  the  index-disc  to  read  the  hundredths  by  turning 
the  index-knob  and  clamp  the  index.  The  auxiliary  arm  is  now 
set;  therefore  the  secondary  arm  is  set  automatically  in  azimuth 
by  virtue  of  its  always  remaining  parallel  to  the  auxiliary  arm. 

Third :  Set  the  primary  arm  to  read  the  number  of  degrees  and 
hundredths  the  target  is  from  the  primary  station.  (The  point  of 
intersection  of  the  fiducial  or  bevel  edges  of  the  primary  and 
secondary  arms  is  the  position  of  the  target  on  the  plotting-board.) 

Fourth:  Slide  the  metal  intersection-block  or  "targ"  along 
the  secondary  arm  until  it  touches  the  edge  of  the  primary.  The 
range  in  yards  can  now  be  readily  read  on  the  scales  marked  on 
these  arms.  (Fig.  62.) 


EXAMINATION  OF  FIRST-CLASS   GUNNERS 


119 


JU 

I 

Q. 


-a 

c 
rt 

c5 

T3 
E 
O 
O 
O 

CO 


120  THE  GUNNER'S  EXAMINER. 

Q.  How  are  the  range  and  azimuth  for  the  directing-gun 
obtained  for  the  same  target  ? 

A.  Move  the  gun-arm  up  to  the  intersecting  edge  of  the  targ, 
and  read  the  range  from  the  scale  on  the  gun-arm.  The  degrees 
of  azimuth  are  read  through  the  reading-opening,  and  the  hun- 
dredths  are  read  on  the  index-disc  for  the  gun-arm. 

Q.  Suppose  the  range  must  be  corrected  for,  say,  150  yards 
more,  and  the  azimuth  for  1.78  degrees  less,  how  can  the  cor- 
rected range  and  corrected  azimuth  be  automatically  read  on  the 
gun- arm  ? 

A.  Turn  the  pinion  on  the  gun-arm  to  move  the  scale  of  the 
range  correction-device  until  2150  is  set.  (The  zero  of  this  scale 
=  2000.)  (By  doing  this  it  is  readily  seen  that  the  gun-arm  range- 
scale  is  just  1 50  yards  nearer  the  gun  center ;  consequently  all  ranges 
read  on  this  scale  will  be  150  yards  more  than  if  the  range  cor- 
rection-device were  at  zero.)  The  azimuth  correction  is  set  by 
turning  the  micrometer  until  the  number  of  even  degrees  of  the 
azimuth  correction  (in  this  case  one  degree  less)  is  read  on  the 
main  scale,  and  the  hundredths  on  the  micrometer.  (Thus  it  is 
seen  that  the  gun  -  arm  will  read  as  many  degrees  and 
hundredths  more  or  less  than  the  true  azimuth  as  the 
number  of  degrees  and  hundredths  of  the  azimuth  correction 
determined. 

Note. — Having  determined  by  the  ballistic  board  the  range 
and  azimuth  corrections,  they  will  usually  answer  for  some  time 
and  thus  avoid  continual  setting  of  these  corrections  on  the 
gun- arm. 

Q.  What  is  the  object  of  the  travel-devices  for  range  and 
azimuth  correction  on  the  gun-arm? 

A.  These  are  to  determine  the  amount  of  change  of 
range  and  azimuth  between  each  observation  of  the  target. 
The  results  thus  obtained  are  given  to  the  range-  and  de- 
flection -  board  operators,  who  use  it  in  finding  the  total  range 
correction  and  the  total  azimuth  correction. 


EXAMINATION  OF  FIRST-CLASS   GUNNERS.  121 

Q.  What  are  all  plotting-boards  principally  used  for? 

A.  For  finding  the  position  of  a  target  whereby  the  range 
and  the  azimuth  of  it  from  any  other  point  (as  a  directing-gun 
of  a  battery)  can  be  determined. 

Q.  What  is  meant  by  the  scale  of  a  plotting-board  ? 

A.  By  the  scale  of  a  plotting-board  is  meant,  one  inch  on 
the  board  is  equal  to  one,  two,  or  so  many  yards  on  the 
ground;  e.g.,  a  scale  of  "one  inch  equals  300  yards"  means, 
one  inch  distance  on  the  board  equals  300  yards  on  the 
ground. 

Q.  How  can  you  determine  the  distance  between  two  points 
on  a  plotting-board  ? 

A.  By  using  the  range-arm  that  is  constructed  for  the  scale 
to  which  the  board  is  drawn,  setting  the  zero  on  one  point  and 
reading  the  number  of  yards  on  the  arm  where  the  point  cuts 
the  scale-edge. 

Q.  How  is  the  longitudinal  deviation  measured  on  the  plot- 
ting-board  ? 

A.  Measure  the  distance  from  the  gun  to  the  target,  and  from 
the  gun  to  the  splash.  Subtract  the  lesser  from  the  greater,  and 
this  will  be  the  longitudinal  deviation,  according  to  the  meaning 
given  in  drill  regulations. 

Q.  How  is  the  lateral  deviation  measured? 

A.  Read  the  azimuth  of  the  target  and  splash  from  the  direct- 
ing-gun. Subtract  the  lesser  from  the  greater:  result  =  lateral 
deviation.  If  the  azimuth  to  the  target  be  greater  than  that 
to  the  splash,  it  is  seen  that  the  deviation  will  be  to  the  left  and 
vice  versa. 

Q.  How  are  open  sights  on  rapid-fire  guns  used? 

A.  The  same  as  on  small-arm  pieces;  i.e.,  the  range  in  yards 
or  elevation  in  degrees  and  minutes  is  set  on  the  rear  sight  accord- 
ing to  how  the  sight  is  graduated,  and  the  gun  is  elevated  and 
traversed  until  the  target,  front  sight,  and  rear  sight  all  come 
in  line. 


122 


THE  GUNNER'S  EXAMINER. 


Q.  Describe  the  5"  R.F.  sight. 

A.  It  consists  of  a  sight-bar  graduated  in  degrees  and  minutes 
(lowest  reading  being  six  minutes),  with  a  sliding  scale  at  the  top 
for  deflection  right  or  left,  the  deflection-scale  reading  to  three 
minutes.  A  range-drum  is  also  geared  to  the  sight-bar,  and 
moves  with  it  in  such  a  manner  that  when  the  piece  has  a  cer- 
tain elevation  it  will  shoot  to  a  distance  equal  to  the  range  on 
the  drum.  This  avoids  using  any  range-table. 

Q.  Describe  the  6-pdr.  R.F.  sight. 

A.  A  simple  bar-sight  graduated  to  yards  with  a  deflection- 
scale  reading  to  three  minutes. 

Q.  How  is  the  deflection-scale  set  on  open  sights  when  it  is 
desired  to  fire  to  right  or  left  ? 

A.  To  fire  right,  move  the  peep-hole  to  the  right;  to  fire  left, 
move  the  peep-hole  to  the  left. 

Q.  From  what  line  is  all  elevation  measured? 

A.  From  the  axis  of  the  bore.     (See  Fig.  63.) 


Gun 


FIG.  63 

Q.  Define  sight  elevation. 

A.  The  angle  between  the  axis  of  the  bore  before  firing  and 
the  line  of  sight.  (See  Figs.  63  and  64.) 

Q.  In  case  shot  strikes  to  the  right  or  left,  and  as  gunner  you 
had  the  sight  on  the  target  when  the  shot  struck,  how  could  you 
correct  your  error  with  a  telescopic  sight  or  open  sights  ? 

A.  Stopping  traversing  at  the  instant  shot  strikes,  move  the 
vertical  hair  rapidly  to  the  splash.  The  sight  is  now  corrected 
for  the  error,  and  its  setting  will  be  correct  for  the  next  shot. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


123 


THE  RANGE-BOARD. 
NOMENCLATURE.     (See  Fig.  65.) 

The  Frame. — The   outside   frame,   or   box,   of    the    instru- 
ment. 

The    Board. — That    upon    which    the    charts    are    pasted. 

K-K. 


Elevation  Arc        |_eve| 


Target 


SIGHT  SET  FOR   "QUADRANT  ELEVATION' 


Elevation  Arc 


SIGHT  SET  FOR  "SIGHT  ELEVATION" 

(EXAGERATED  DIAGRAMS.) 

FIG.  64. 


The  Ruler. — The  balance  wooden  strip  to  which  the  metal 
scale  and  slides  are  attached.  X-X. 

The  Scale. — The  fixed  graduated  scale  on  the  ruler. 
m-m. 

The  Bar. — The  metal  rod  or  bar  which  slides  on  the  top  of 
the  scale. 


124  THE  GUNNER'S  EXAMINER. 

The  Register. — The  fixed  point  in  the  center  of  the  bar.     a. 

The  Trammel — The  pointer  which  slides  on  the  bar.     b. 

The  Pointer.     The  pointer  at  the  top  of  the  trammel. 

The  Index. — The  lower  point  on  the  trammel. 

Normals. — The  straight  vertical  lines  in  each  set  of  curves. 

The  String. — The  cord  on  the  right  side  of  the  board  used  in 
determining  travel. 

The  Travel- scale. — Scales  for  setting  the  string. 

Prediction- scale. — Vertical  lines  on  the  right  side  of  the  board, 
used  in  determining  the  travel  during  the  observing  interval. 

ADJUSTMENT. 

Adjust  the  ruler  by  means  of  the  adjusting-screw  on  the  left, 
so  that  its  upper  edge  coincides  with  the  parallel  lines  on  the  board. 

OPERATION. 

The  bar  is  clamped  by  means  of  the  screw  near  the  left  end  of 
the  luler. 

The  bar  must  be  held  firmly  while  moving  the  trammel.  In 
making  corrections  for  artillery  fire  the  following  data,  as  obtained 
at  the  opening  of  the  action,  will  usually  suffice  for  the  entire  action. 

Density  of  the  air, 
Velocity  o)  the  wind, 
Azimuth  oj  the  wind, 
Height  of  tide. 

The  range  effects  and  deviating  effects  of  the  wind  must  be 
obtained  for  each  shot.  Tide  should  be  changed  at  least  every 
half-hour.  As  soon  as  the  density  of  the  air  is  ascertained  the 
computer  will  insert  a  pin,  or  set  the  pointer  at  the  top  of  the 
corresponding  curve.  The  same  will  be  done  for  height  of  tide. 

The  muzzle  velocity  to  be  used  for  the  first  shot  will  be  marked 
in  a  similar  mannei  as  directed  by  the  range  officer.  The  wind- 
component  device  having  been  set  for  the  azimuth  and  velocity 
of  the  wind  and  the  azimuth  of  the  target,  the  computer  will  note 


EXAMINATION  OF  FIRST-CLASS   GUNNERS. 


125 


126  THE   GUNNER'S  EXAMINER. 

the  reference-number  and  set  the  pointer  at  the  top  of  the  wind- 
curve  having  that  number. 

As  soon  as  he  receives  the  travel  reference-number  he  will 
set  the  string  accordingly,  using  the  scale  for  the  observing  interval 
used. 

To  determine  correction. — As  soon  as  the  approximate  range  is 
received,  the  computer  sets  the  ruler  for  the  range  and  the  index 
at  zero;  he  then  slides  the  trammel  to  the  left  until  the  pointer 
is  opposite  the  atmosphere  curve  as  indicated  by  the  pointers  e,  /, 
g,  etc.,  holding  the  bar  in  place  with  the  left  hand.  He  then  slides 
the  bar  until  the  pointer  is  at  normal  for  atmo3phere;  this  com- 
pletes the  correction  for  atmosphere. 

He  then  proceeds  in  the  same  manner  for  wind  and  tide, 
always  sliding  the  trammel  until  the  pointer  is  at  the  indicated 
curve,  holding  the  bar  in  place  with  the  left  hand  and  then  sliding 
the  bar  until  the  pointer  is  at  normal. 

If  the  muzzle  velocity  is  normal,  no  correction  is  made  for 
velocity.  If,  however,  the  muzzle  velocity  is  not  normal,  he 
makes  a  correction  for  muzzle  velocity  in  a  similar  manner  as  for 
other  data. 

The  above  corrections  are  made  before  the  travel  is  received. 
The  computer  clamps  the  bar  and  then  waits  until  he  receives  the 
travel. 

As  soon  as  the  travel  is  received,  he  sets  the  string,  slides 
trammel  until  the  pointer  is  opposite  the  string,  unclamps  the  bar 
and  moves  it  until  the  pointer  is  opposite  the  normal;  this  adds 
the  correction  for  travel  during  the  time  of  flight. 

He  then  notes  the  total  travel  during  the  observing  interval, 
which  is  indicated  by  the  position  of  the  string  on  the  travel- scale 
corresponding  to  the  observing  interval  used.  He  slides  the 
trammel  so  that  the  pointer  will  be  at  the  vertical  line  correspond- 
ing to  the  total  travel  during  the  observing  interval,  and  then 
slides  the  bar  to  the  normal;  this  adds  the  travel  during  the 
observing  interval.  He  now  clamps  the  bar.  The  register  now 
indicates  the  total  correction  to  be  applied  to  the  arm. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS.  127 

Trial-shots.— The  gun  is  laid  so  that  the  shot  should  have  a 
certain  range,  all  corrections  having  been  determined  as  described 
above,  except  of  course  that  for  travel. 

The  bar  is  set  with  the  index  at  zero,  and  the  trammel  is  set 
at  the  muzzle  velocity  used  in  the  computation  for  the  shot. 

The  gun  is  fired  and  the  range  of  the  shot  is  plotted.  The 
range  officer  determines  how  much  the  shot  has  fallen  short  or 
gone  beyond,  and  announces  the  result  as  plus  or  minus  so  many 
yards.  The  computer  moves  the  bar  plus  or  minus  the  number 
of  yards  announced,  using  the  scale  for  this  purpose. 

The  pointer  now  indicates  the  muzzle  velocity  to  be  used  in 
computing  the  next  shot.  The  velocity  pointer  is  moved  accord- 
ingly. 

If  a  second  trial  shot  is  used,  the  corrections  are  computed  as 
before,  using,  however,  the  new  muzzle  velocity  as  determined 
from  the  first  shot. 

In  determining  a  second  corrected  muzzle  velocity  the  bar 
should  be  moved  for  but  half  the  longitudinal  deviation  of  the 
shot  from  the  expected  range ;  the  pointer  then  marks  the  velocity 
to  be  used  for  the  next  shot. 

In  case  a  third  trial  shot  is  used  the  process  is  the  same  except 
that  the  bar  is  moved  for  but  one  third  of  the  longitudinal  deviation. 

The  curves  are  given  for  every  ten  yards  of  range,  for  every 
ten  per  cent  of  weight  of  air,  and  for  every  ten  miles  of  wind,  etc. 

For  conditions  in  which  the  values  lie  between  these  readings, 
the  trammel  can  readily  be  set  by  the  eye  sufficiently  close  for  all 
practical  purposes. 

EXAMPLE:  Range  7000;  atmosphere  20;  wind  70;  velocity 
2260;  travel  400;  tide  +10.  Find  the  correction  to  be  applied 
to  the  gun- arm. 

SOLUTION:  I.  Set  ruler  XX  at  7000  on  scale  KK. 

II.  Set  pointer  a  at  2000  on  scale  MM. 
III.  Set  pointer  e  at  20;  /at  70;  g  at  + 10;    h  at 
2260,  string  cc  at  400  on  2o-second  interval 
line,  and    scale    dd   such    that    the    number 


128  THE   GUNNER'S  EXAMINER. 

400  cuts  the  intersection  of  the  string  with 
ruler  XX. 

IV.  Set    pointer    b    at    16    (atmosphere    normal); 
move  slide  z  till  b  cuts  the  20  curve  of  atmo- 
sphere. 
V.  Set  b  at  50  (zero  wind)  and  slide  z  till  b  cuts 

the  70  curve. 

VI.  Set  b  at  o  tide  and  slide  z  till  b  cuts  +10. 
VII.  Set    b    at    2200  I.  V.    and    slide   z   till    b  cuts 

2260. 

VIII.  Set  b  at  400  on  scale  dd  and  slide  z  till  &  cuts 
300  (normal)  on  scale  dd. 

The  range  correction  is  now  found  on  scale 
mm  opposite  pointer  a.  This  number  is 
now  set  on  the  gun-arm  of  the  plotting- 
board  and  each  next  plotted  position  will  read 
on  the  range-scale  of  the  gun-arm  just  that 
many  yards  more  or  less  than  the  true  range, 
i.e.,  the  corrected  range. 
See  Fig.  65. 

THE  DEFLECTION-BOARD. 
NOMENCLATURE. 

Platen. — The  rectangular  sliding  frame. 

Wind- arm. — The  arm  pivoted  to  the  board  on  the  left  of  the 
platen. 

Wind- component  Scale. — The  scale  above  the  movable  end  of 
the  wind -arm. 

Drift- curve. — The  curved  edge  of  the  metal  plate  attached  to 
the  left  end  of  the  platen. 

Travel- arm. — The  arm  pivoted  on  the  platen. 

Azimuth  Correction- scale. — The  sliding  scale  below  the  platen. 

Deflection-scale. — The  fixed  scale  immediately  above  the  azi- 
muth correction-scale. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


129 


130  THE  GUNNER'S  EXAMINER, 

Travel-scale. — A  scale  for  making  corrections  for  angular 
travel  of  the  target;  there  are  two,  one  below  the  azimuth  correc- 
tion-scale and  one  on  the  platen. 

"T"  Square.  — The  sliding  "T"  square  having  the  time 
graduations  at  one  edge,  corresponding  to  given  ranges. 

OPERATION. 

Place  the  travel- scale  on  the  platen  in  the  lower  or  upper 
position  according  as  the  observing  interval  is  10  or  20  sec- 
onds. 

As  soon  as  the  wind -component  device  is  set  note  the  deflection 
reference-number  indicated,  and  set  the  wind-arm  to  the  corre- 
sponding reading  on  the  wind-component  scale. 

Set  the  platen  so  that  the  point  of  the  drift-curve  corresponding 
to  the  given  range  will  be  accurately  over  the  right-hand  edge  of 
the  wind -arm. 

As  soon  as  the  reference-number  indicating  the  angular  travel 
of  the  target  during  the  observing  interval  is  announced,  set  the 
travel-arm  (right  edge)  for  that  travel  by  the  travel-scale  on  the 
platen  and  set  the  azimuth  correction-scale  for  the  same  travel 
by  means  of  the  travel-scale  below  it. 

Set  the  "T"  square  so  that  the  point  of  its  scale  corresponding 
to  the  given  range  will  be  accurately  over  the  right  edge  of  the 
travel-arm. 

The  azimuth  correction  to  be  applied  to  the  gun-arm  in  all 
cases  is  then  read  from  the  azimuth  correction  scale  at  the  bevel 
edge  of  the  "T"  square. 

When  Case  I  or  II  is  being  used  the  deflection  to  be  sent  to 
the  guns  is  read  from  the  deflection-scale  at  the  bevel  edge  of  the 
"T"  square. 

After  the  second  observation  the  corrected  range  determined 
is  used  in  setting  the  platen  and  "T"  square. 

See  Fig.  60. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS.  131 

Q.  How  do  the  divisions  on  the  azimuth-subscale  and  the 
deflection-scale  of  the  sights  compare  with  one  another? 

A.  They  are  equal — the  least  reading  on  the  former  =5 
hundredths,  and  on  the  sight-scale  one  point  or  division  =5 
hundredths  or  3  minutes. 

Q.  How  are  the  predicted  range  and  predicted  azimuth  ob- 
tained ? 

A.  It  is  now,  under  the  new  system  of  fire  direction,  obtained 
by  means  of  the  travel  correction  on  the  range  correction  and 
azimuth  correction-board.  If  these  new  boards  are  not  yet 
issued,  the  use  of  a  range-keeper's  range  prediction-scale  and 
a  gunner's  azimuth  prediction-scale  determines  them  at  the  gun. 
The  old  method  was  by  plotting  several  positions  of  a  target 
on  the  plotting-board  and  using  a  prediction-ruler,  whence  the 
predicted  point  was  obtained. 

Q.  Define  quadrant  elevation. 

A.  The  angle  between  the  axis  of  the  bore  before  firing  and 
the  horizontal  plane.  (See  Figs.  63  and  64.) 

Q.  What  is  the  difference  between  quadrant  and  sight  eleva- 
tion? 

A.  Where  the  gun  is  above  the  target,  sight  elevation  equals 
quadrant  elevation  plus  the  angular  depression  of  the  target. 
Where  the  gun  is  below  the  target,  sight  elevation  equals  quad- 
rant elevation  minus  the  angular  elevation  of  the  target. 

Q.  How  is  the  gunner's  quadrant  used? 

A.  It  is  used  principally  in  giving  elevation  to  mortars  by 
first  setting  the  movable  arm  such  that  the  knife-edged  tooth 
engages  in  an  even-degree  mark  on  the  rack,  and  by  moving  the 
sliding  level  to  read  the  exact  number  of  minutes.  Then  it  is 
placed  on  its  seat  at  the  breech,  being  careful  to  see  that  the 
arrow  points  in  the  direction  of  the  line  of  fire,  and  by  elevating 
or  depressing  the  piece  until  the  bubble  comes  in  the  middle  the 
rmrtar  or  piece  will  be  set  at  the  elevation  set  on  the  quadrant. 
(3ee  Fig.  67.) 


132 


THE  GUNNER'S  EXAMINER. 


Q.  Point   out   the   following   parts   of  the  telescopic  sight: 
Telescope,  objective,  eyepiece,  erecting-prisms,  trunnions,  level- 


SHOWING  METHOD  OF  USII> 

GUNNER'S  QUADRANT. 
MORTAR  SET  AT  45°  ELEVATION* 


-Toothed  Clamp 
Clamp  Screw 
uminum  Body 


,    THE  GUNNER'S  QUADRANT. 

FIG.  67. 


ing-lug,  leveling-screw,  cross-level,  elevation-arc,  elevating-screw, 
vernier,  focusing-collar,  deflection-screw,  deflection-scale,  microm- 
eter, disc,  and  telescope-level.  (See  Fig.  68.) 


Micrometer  Disc  fb 

Reading  Minutes 

Levelling  Screw. 


levating  Screw 

.Objective 


Trunnio 
Bed 


Focussing  Collar 

-Telescope  Tube 
Level 

Deflectfon  Scale  of  Degrees 
and  half  Degrees 

Deflection  Screw 

Deflection  Scale  of  Minutes 
4\  (one  dly.  =  3  min...) 

Elevation  Arc/     <,ernier      |    XEye  Piece 

Cross  Level 

THE  TELESCOPIC  SIGHT 
MODEL  1898. 

FIG.  68. 


Q.  How  is  deflection  set  on  it  ? 

A.  By  moving  the  deflection-screw  the    vertical   cross-wire 
moves. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS.  133 

Q.  How  is  deflection  set  to  fire  right  and  to  fire  left? 

A.  Move  the  vertical  hair  to  the  right  to  fire  left,  move  it  to 
the  left  to  fire  right,  by  turning  the  deflection-screw. 

Q.  How  is  elevation  set  on  it  ? 

A.  Set  the  zero  of  the  vernier  opposite  the  mark  on  the  limb 
representing  the  number  of  even  degrees  of  the  given  elevation. 
Then  turn  the  micrometer-disc  by  turning  the  elevation-screw 
until  the  given  number  of  minutes  is  read  on  it.  The  sight  is 
then  set  on  the  trunnion-bracket  and  the  piece  elevated  till  the 
bubble  comes  in  the  middle  for  quadrant  elevation  or  till  the 
horizontal  cross-hair  cuts  the  water  line  of  target  for  sight  eleva- 
tion. The  gun  then  has  the  elevation  set  on  the  sight. 

Q.  What  is  the  lowest  reading  of  the  vernier  on  the  elevation- 
arc? 

A.  Two  minutes. 

Q.  What  is  the  lowest  reading  of  the  deflection-scale? 

A.  Three  minutes. 

Q.  Why  is  it  necessary  to  elevate  the  gun  till  the  bubble  on 
the  telescope-level  comes  in  the  middle,  to  set  the  gun  for  quad- 
rant elevation? 

A.  Because  by  definition  quadrant  elevation  is  the  angle 
between  the  axis  of  the  bore  and  the  horizontal  plane,  and  when 
the  bubble  is  in  the  center  of  the  level  the  telescope  is  horizontal 
and  the  axis  of  the  gun  makes  an  angle  with  it  equal  to  the  eleva- 
tion set  on  the  arc. 

Q.  Name  and  point  out  the  following  parts  of  the  rapid-fire 
sight :  Telescope,  objective,  eyepiece,  interior  and  exterior  deflec- 
tion-scales, micrometer-head,  deflection-screw,  open  sights,  dew- 
cap,  lugs,  and  thumb-screws. 

A.  See  Fig.  70. 

Q.  What  is  one  point  on  the  deflection-scale  equal  to  at  the 
target  ? 

A.  One  five-hundredth  of    the    range  in  yards;     thus  one 


I34  THE   GUNNER'S  EXAMINER. 

point  equals  2  yards  at  1000  yards,  4  yards  at  2000  yards,  and 
so  on. 

Q.  EXAMPLE  :  The  range  *s  5000  yards,  and  the  drift  for  that 
range  is  found  in  the  range-table  to  be  12  minutes;  how  would 
you  set  your  deflection-scale  on  the  telescopic  sight? 

A.  "Fire  lejt"  12  minutes,  or  4  points. 

Q.  Why? 

A.  Because  drift  in  our  service  is  always  to  the  right,  and  to 
overcome  this  drift  and  make  the  projectile  hit  the  target  we 
will  have  to  fire  to  the  left  this  12  minutes  due  to  drift. 

Q.  EXAMPLE:  The  range  is  5000  yards,  and  the  component 
of  the  wind  perpendicular  to  the  line  of  fire  is  20  miles,  giving 
from  the  range-table  correction  for  drift  equal  to  12  minutes  and 
wind  6  minutes.  The  wind  is  blowing  from  right  to  left.  How 
would  you  set  your  sight  ? 

A.  "Fire  left"  6  minutes. 

Q.  Why? 

A.  Because,  as  shown  above,  the  drift  alone  would  require 
the  sight  to  be  set  at  "Fire  lejt"  12  minutes,  and  if  the  wind  cor- 
rection is  6  minutes  and  is  blowing  from  right  to  left,  to  overcome 
this  wind  and  make  the  projectile  hit  the  target  we  would  have 
to  "Fire  right"  6  minutes.  Therefore,  if  the  total  setting  of 
the  sight  is  to  be  "Fire  left''  12  minutes  plus  "Fire  right"  6 
minutes,  the  final  or  resultant  setting  should  be  "Fire  lejt"  6 
minutes. 

Note. — The  corrections  for  wind  and  drift  are  usually  found 
at  the  same  time  from  a  chart,  correction-board,  or  table. 

Q.  EXAMPLE:  The  time  of  flight  is  10  seconds  (this  is  found 
from  the  gun  commander's  range-table,  knowing  the  range); 
how  would  you  determine  the  correction  for  travel  with  a  tele- 
scopic sight  ? 

A.  Set  the  sight  at  zero.  Traverse  the  gun  until  the  vertical 
hair  cuts  the  target.  Signal:  "Stop  traversing,"  and  count  the 
number  of  seconds  time  of  flight  (10),  moving  by  the  right 


EXAMINATION  OF  FIRST-CLASS  GUNNERS.  135 

hand  the  deflection-screw,  to  keep  the  vertical  hair  on  the  target. 
When.  10  seconds  are  counted  stop  turning  the  deflection-screw. 
Where  the  vertical  hair  now  rests  is  the  correction  for  "travel 
during  time  of  flight."  Since  to  "Fire  left"  we  move  the  verti- 
cal hair  to  the  right,  this  correction  for  travel  found  will  have 
to  be  set  for  "Fire  left,"  or  on  the  other  side  of  the  scale,  if  the 
target  is  moving  from  right  to  left.  If  it  is  moving  from  left  to 
right,  the  correction  found  will  have  to  be  set  "Fire  right"  In 
other  words,  always  set  the  cross-hair  in  the  opposite  direction 
from  the  motion  of  the  vessel  in  making  the  correction  for  travel. 
This  also  applies  to  open  sights. 

Q.  EXAMPLE:  If  you  were  given  the  range,  a  gun  command- 
er's range-table,  a  correction  for  wind  and  drift  equal  to  "Fire 
left"  9  minutes,  and  the  target  were  moving  from  right  to  left, 
how  would  you  proceed  to  determine  the  setting  of  your  sight? 

A.  First,  determine  by  the  above  method  the  correction  for 
travel  during  time  of  flight  (time  of  flight  being  found  in  the  gun 
commander's  range-table).  Set  this  on  the  sight.  Suppose  it 
were  "Fire  left"  3  minutes. 

Second,  use  this  position  of  the  vertical  hair  as  a  new  zero, 
and  move  the  vertical  hair  to  "Fire  left"  12  minutes.  That  is, 
"Fire  left"  3  minutes  plus  "Fire  left"  9  minutes  equals  "Fire 
left"  12  minutes. 

If  the  travel  had  been  "Fire  right"  3  minutes,  then  by  moving 
the  scale  "Fire  left"  9  minutes,  the  final  setting  of  the  sight  would 
have  been  "Fire  left"  6  minutes. 

Q.  From  the  table  on  page  129  find  the  number  of  yards 
3  points  on  the  telescopic  sight  are  equal  to  at  7000  yards 
range. 

A.  1 8  yards. 


THE   GUNNER'S  EXAMINER. 


m 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


137 


3-INCH  RAPID-FIRE  GUN-SIGHT. 

Dew  Cap 


Thumb  Screw 


Thumb  Screw 
Open  Sight 


Exterior  Deflection 
Seals 


Deflection  Screw 


Deflection  Scale 


138 


THE   GUNNERS  EXAMINER. 


2.  Point  or   describe  the   location  of  the    following  parts  of 
the  telescopic  sights,  Model  1904: 


Eye-lens  cover. 

Dial. 

Focusing  ring. 

Peep-sight. 

Eye- end  telescope  clamp. 

Deflection  woim  knob. 

Telescope  tube. 

Elevation  rack. 

Cell-end  telescope  clamp. 

Objective  shutter. 

Cradle. 

Cross  sight. 

Yoke-cap. 

Deflection-pointer  bracket. 

Fulcrum. 

Elevating  wheel  and  hub. 

Sight-bracket. 

Plug  connection  for  lamps. 

Lamp  -  holder    for     deflection 

scale. 
Range  drum. 

A.  See  Figs.  71  and  72. 


Gear-case  cover  and  cover  for 

range  drum. 
Telescope  lamp-holder. 
Sight-shank  elevation- scale. 
Elevation-guide. 
Sight-arm. 
Yoke-shaft. 
Bearing  for  yoke. 
Yoke. 
Lamp-bracket  for  range  drum 

and  elevation- scale. 
Elevation  worm. 
Focusing  sleeve  nut. 
Deflection  scale. 
Elevating  gear-shaft. 
Deflection  worm. 
Eye-lens. 
Field  lens. 
Cross-wire  ring. 
Cross  wires. 

Erecting  prisms  (Porro). 
Objective. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS.  141 

TABLE  OF  VALUES  IN  YARDS  OF  POINTS  OF  DEFLECTION. 


Min   

3 

6 

9 

12 

15 

Points  

I 

2 

3 

4 

5 

Range. 

Value  of  Points  in  Yards. 

1000  
2000  

3000  
4000  .  . 

I 
2 

3 
3 

4 

1 

8 

2 

4 
6 
6 
8 
10 

12 
14 

16 

6 
9 
9 

12 

;§ 

21 
24 

4 
8 

12 
12 

16 

2O 
24 
28 
32 

d 

15 

15 

20 
25 
3° 

35 
40 

cooo  

6000  
7000  
8000 

QOOO  . 

10000.   

9 

18 

27 

36 

45 

Note. — This  table  is  only  approximate.  It  is  true  within  i 
yard,  which  is  sufficiently  accurate  for  all  firing  under  Case  II. 

Q.  Where  is  the  sight  placed  under  cases  one,  two,  and  three  ? 

A.  On  the  trunnion  for  case  one,  to  give  both  elevation  and 
direction.  On  the  sight  standard  for  case  two,  to  give  direction 
only  (quadrant  elevation  is  set  by  the  elevating- arc).  It  is  not 
intended  to  be  used  at  all  in  case  three,  but,  of  course,  it  could 
where  the  quadrant  elevation  is  to  be  set  by  the  sight  instead 
of  by  the  elevation-arc.  It  will  then  have  to  be  placed  on  the 
trunnions. 

Q.  Define  cases  one,  two,  and  three. 

A.  Case  one,  where  direction  and  elevation  are  given  by  the 
sight  on  the  trunnion.  Case  two,  where  direction  is  given  by  the 
sight,  and  elevation  by  the  quadrant  or  elevating-arc.  .Case 
three,  where  direction  is  given  by  the  azimuth-circle,  and  eleva- 
tion by  the  quadrant  or  arc, 

Q.  What  is  the  difference  between  the  axis  of  the  bore  and 
the  line  of  departure  ? 

A.  The  jump.     (See  Fig.  63.) 

Q.  What  is  the  line  of  sight? 

A.  Line  joining  the  target,  the  point  of  the  front  sight  and 
the  peep  of  the  rear  sight ;  or  with  telescopic  sights,  the  line  join- 


142  THE   GUNNER'S  EXAMINER. 

ing  the  target  and  the  intersection  of  the  vertical  and  horizontal 
hairs  in  the  sight.     (See  Fig.  63.) 

Q.  Define  time  of  flight. 

A.  The  time  it  takes  the  projectile  to  leave  the  bore  till  it 
strikes. 

Q.  What  is  a  tangent  ? 

A.  A  straight  line  which  touches  but  one  point  on  the  circum- 
ference of  a  circle  and  is  perpendicular  to  the  radius  at  that  point. 

Q.  Define  angle  of  fall. 

A.  It  is  the  angle  which  the  tangent  to  the  trajectory  at  the 
point  of  impact  makes  w.'th  a  line  parallel  to  the  line  of  sight  at 
thi  point. 

Q.  What  is  the  line  of  departure  ? 

A.  The  prolonged  axis  of  the  bore  at  the  moment  the  pro- 
jectile leaves  the  muzzle. 

Q.  What  is  the  line  of  fire  ? 

A.  The  prolonged  axis  of  the  bore  before  the  gun  is  fired. 

Q.  What  is  the  axis  of  the  bore  ? 

A.  The  line  passing  through  the  centre  of  the  bore  from  breech 
to  muzzle. 

Q.  What  is  the  angle  of  departure  ? 

A.  The  angle  included  between  the  line  of  departure  and  the 
horizontal  plane. 

Q.  Define  drift. 

A.  It  is  the  deviation  due  to  the  rifling  in  the  gun  to  the  right 
or  left  of  the  vertical  plane  passing  through  the  axis  of  the  bore, 
or  plane  of  fire.  It  is  always  to  the  right  in  the  U.  S.  service. 

Q.  To  what  in  a  telescopic  sight  does  the  front  sight  on  an 
open  sight  correspond  ? 

A.  The  intersection  of  the  cross-hairs. 

Q.  To  what  does  the  rear  sight  correspond? 

A.  The  eye-lens. 

Q.  What  is  the  trajectory  ? 

A.  The  path  of  the  projectile  in  the  air. 

Q.  How  is  the  velocity  of  the  wind  determined? 

A.  By  the  anemometer.     First  take  the  reading  of  the  discs 


EXAMINATION  OF  FIRST-CLASS  GUNNERS.  143 

on  the  anemometer  and  note  the  time.  After  six  minutes  have 
elapsed  read  the  scales.  Take  the  difference  of  the  scales  and 
multiply  by  10,  which  gives  the  velocity.  (See  Fig.  73.) 

For  example:  Suppose  at  10:05  A-M-  the  reading  is  62  miles, 
and  at  10:11  A.M.  the  reading  is  63  miles.  If  in  six  minutes  it 
goes  one  mile,  in  sixty  minutes  it  will  go  ten  times,  or  ten  miles 
per  hour. 

THE  ANEMOMETER. 


FIG. 

Q.  How  are  the  components  of  the  wind  in  the  direction  of 
the  line  of  fire  and  in  a  lateral  direction  determined  ?  (See  Fig.  74.) 

A.  First :  Set  the  arrow  on  the  disc  to  read  the  azimuth  of  the 
wind.  (This  is  done  automatically.) 

Second :  Set  the  little  lever-arm  at  the  azimuth  of  the  line  of  fire. 

Third :   At  the  point  on  the  lever-arm  reading  the  velocity  of 


144 


THE  GUNNER'S  EXAMINER. 


the  wind  as  determined  by  the  anemometer,  run  the  finger  or  a 
pencil  along  the  nearest  line  toward  the  arrow,  and  where  this 
line  cuts  the  arrow  is  read  the  longitudinal  component  or  the 
component  in  the  direction  of  the  line  of  fire. 


FIG.  74. 

Q.  How  are  the  wind  components  determined  by  the  "new 
method"? 

A.    i°  Set  tar  get- pointer  to  velocity  of  wind  on  target-arm. 
2°  Set  ring  to  azimuth  of  wind. 
3°  Set  target-arm  to  azimuth  of  gun. 
4°  Components   are  now  read  on  dial  from  the  point  in- 
dicated by  the  tar  get- pointer.    (See  Fig.  75.) 


EXAMINATION  OF  FIRST-CLASS   GUNNERS. 


145 


WIND    COMPONENT.     (New  Method.) 


FIG.  75. 


146 


THE   GUNNER'S  EXAMINER 
THE   AEROSCOPE. 


deter. 

mined  from  the 
Weather  Vane. 


Determined  froru 
the  Anemometei 
and  Stopwatch. 


Determined  by  the 
readings  of  the  Baro- 
meter and  Thermometer. 


Snap  Switch 


Push  Buttons  for 
moving  Pointers 
on  Dials. 


FIG.  76. 


EXAMINATION  OF  FIRST-CLASS   GUNNERS. 


'47 


DIFFERENCE  CHART 

for 
10  in.  B.L.R.  No.1 

In  Battery ,    Fort 

Directing  Gun  of  that  Battery 

10  in.  B.L.R.  No. 2 
Azimuth  of  Gun  No.1  from  Directing 

Gun,  79°03' 
Gun  Displacement,  38  Ya 


rds 


i48 


THE   GUNNER'S  EXAMINER. 


Fourth:  From  this  same  point  on  the  little  lever-arm  run  a 
pencil  along  the  nearest  line  parallel  to  the  arrow,  and  where  it 
intersects  the  diameter  of  the  disc  perpendicular  to  the  arrow  is 
read  the  component  in  the  direction  of  deflection  or  the  lateral 
component. 

Q.  What  is  a  difference  chart? 

A.  One  that  determines  the  differences  in  azimuth  and  range 
between  the  directing-gun  and  the  gun  for  which  it  is  constructed. 
It  consists  of  a  board  having  drawn  on  it  circles  of  different 
diameters,  which  are  the  azimuth  difference  circles  (the  amounts 
being  written  on  each  circle).  (See  Fig.  77.) 

Q.  How  is  it  used  ? 

A.  First:  Set  the  range-arm  on  the  given  azimuth. 

Second:  Run  the  finger  to  the  given  range  on  the  range-arm. 

Third :  The  azimuth  difference  is  read  on  the  nearest  circle  that 
cuts  the  point  where  the  finger  last  rests,  and  the  range  difference 
is  read  on  the  scale  in  red  ink  along  the  azimuth  circle  of  the 
board.  (See  Fig.  77.) 

Q.  What  is  meant  by  muzzle  velocity? 

A.  The  number  of  feet  per  second  a  projectile  is  moving  at  the 
time  it  leaves  the  muzzle  of  the  gun.  It  is  also  called  Initial  Velocity. 

Q.  From  the  following  gun  commanders'  range-scale  find  the 
time  of  flight,  sight  elevation,  and  quadrant  elevation  for  4120 
yards  range. 

GUN  COMMANDERS'  RANGE-SCALE. 
I.  V.  2200.         8-inch  B.  L.  R.         Smokeless  powder. 


Quadrant  Elevation. 

Sight  Elevation. 

Range. 

Seconds. 

Degrees. 

Minutes. 

Degrees. 

Minutes. 

+  4 

16 

4100 

—  I 

3 

61 

+  4 

18 

4120 

—  I 

i 

+  4 

20 

4140 

—  o 

58 

+  4 

23 

4160 

—  o 

56 

7t 

+  4 

26 

4180 

—  o 

54 

+  4 

28 

4200 

—  o 

5i 

+  4 

31 

4220 

—  o 

49 

8! 

EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


149 


ELECTRICAL  DEVICE  FOR  OPERATING  ANEMOMETER 
STOP-WATCH. 


FIG.  78. 


THE   GUNNER'S  EXAMINER. 


A.  6}  seconds,  about; 
(elevation). 


i°  i'  minus  (depression);   4°  18'  plus 


THE  ATMOSPHERE-BOARD. 

Q.  Describe  the  atmosphere-board. 

A.  This  is  merely  a  graphic  table  by  means  of  which  the 
reference-numbers  to  be  recorded  on  the  atmosphere-aeroscope 
indicator  can  be  determined  from  the  readings  of  the  barometer 
and  thermometer.  The  arguments  are  barometer  and  thermom- 

ATMOSPHERE  BOARD 


100 

r,i 


.2 

-  .4 

-  .6 
.8 


-281 


FIG.  79- 

eter  readings,  and  the  reference-numbers  are  indicated  by  diagonal 
lines.  The  thermometer  axis  is  horizontal  and  the  barometer 
axis  is  vertical.  To  increase  the  ease  and  rapidity  of  reading 
the  barometer  scale  is  graduated  on  a  movable  T  square. 

The  method  of  construction  is  shown  in  Fig.  79. 

Operation. — Set  the  T  square  for  the  thermometer  reading  and 
note  the  diagonal  line  which  intersects  the  fiducial  edge  of  the  T 
square  the  nearest  to  the  barometer  reading.  The  atmosphere 
dial  is  graduated  to  J  per  cent.  The  reading  of  the  board  should 
be  taken  to  the  nearest  half  reference-number. 


EXAMINATION  OF  FIRST  CLASS   GUNNERS.  ^ 

SPECIAL  APPARATUS  FOR  MORTARS. 

Q.  Point  to  the  following  parts  of  the  Mortar  Gun-arm: 
Movable  gun-arm.  Elevations. 

Yards  range.  Time  of  flight. 

Overlap.  Zones. 

A.  See  Fig.  80. 

SET-FORWARD  RULER. 

Q.  Describe  the  set-forward  ruler  and  explain  its  use. 

A.  First  find  the  travel  in  yards  per  minute.  Set  the  pointer 
(a)  on  the  slide  (b)  at  the  number  of  yards  on  the  scale  of  "yards 
travel  per  minute  (c)."  Then  on  gun-arm  get  time  of  flight  for 
that  point.  The  "  set-forward  point"  will  be  the  reading  opposite 
time  of  flight  on  the  scale  of  "  yards  travel  during  time  of  flight +  i 
minute  (d)."  (See  Fig.  81.) 

EXAMPLE. — After  taking  four  observations  on  a  target  we  find 
that  in  one  minute's  time  it  has  traveled  200  yards.  Set  the 
pointer  (a)  at  200  yards  on  the  scale  (c).  On  the  gun-arm  we 
see  that  the  time  of  flight  for  this  point  is  sixty  seconds.  There- 
fore our  set-forward  point  is  400  yards,  as  this  is  the  reading  exactly 
opposite  the  time  of  flight  on  scale  (d).  (See  Fig.  81.) 

Q.  Describe  and  explain  the  use  of  the  prediction  scale. 

A.  The  prediction  scale  is  graduated  in  the  same  manner  as 
the  gun-arm  (i"  =  3oo  yards),  and  is  used  for  finding  the  pre- 
dicted point.  After  having  marked  four  points  on  the  board, 
showing  the  course  of  the  target,  place  the  prediction  scale  so 
that  zero  (o)  is  on  the  last  point,  or  reading,  and  then  mark  off 
as  many  yards  in  advance  of  the  last  point  as  the  first  reads  from 
zero.  This  point  is  known  as  the  predicted  point,  and  is  used 
by  the  range  officer  only.  As  soon  as  the  predicted  point  is 
found  he  sets  his  azimuth  instrument  at  the  given  azimuth  and 
when  the  target  crosses  the  vertical  wire  in  the  instrument,  he 
gives  the  signal  "Fire."  (See  Fig.  82.) 


THE  GUNNER'S  EXAMINER 
GUN  ARM  FOR  MORTARS. 

/• — Moveable  Gun 


\ 

yV 

% 

\ 

59    = 

/ 

^ 

400  —  f= 

>  Rang< 

65 

37 

58    = 

600-| 
E 

Zone 

57    - 

56    ~ 

E 

44 

55 

700—  E: 

EZ 

800—  | 

54 

53 

43 

5?     - 

63    - 

34 

51     - 

900-| 

50    - 

62    ~ 

32 

49     - 

— 

47     = 

E 

61    ~ 

E 
1100—= 

1200—  J= 
1300  —  E 

Elevations 

42 

41 

40 
39 

60    - 

59    - 

5^ 

•E 

58   - 

65 

14uO—  -= 

57    : 

1600—  = 
1600  —  E 

E 

1700  —  = 

56    : 

55    ^ 

54    = 

64 

--.'     •= 

53 

1800—^ 

52 

1900  —  = 

Overlap 

,'T 

X 

mes 

37 

36 
35 
34 

51    - 

63 

50    - 

2000^ 

49    - 

48    - 

2100  —  E 

'47    - 

62 

45  -E 

( 

^\ 

of  F 

48 

2200—  E 
2300—  E 
2400  —  E 

61 

\^ 

light 
Fl 

47 

5 

G.  I 

60 

2500—  E 

P 

Ele 

5o. 

vatk 

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I              I 

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CO    l~ 

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E=roo 

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0911-^1 

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=      .j.            ^_  §EE 

09  L-^JE 
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TIME  OF  FLIGHT  — 
IN  SECONDS  (Tfl 
MARK  TO  TRAVElN 

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II 

I54  THE  GUNNERS  EXAMINER. 

DEFLECTION  SCALE. 

Q.  Describe  the  deflection  scale  and  explain  its  use. 
A.  The  deflection  scale  is  used  to  determine  azimuth  correc- 
tions for  mortars.  After  the  " set-forward  point"  has  been 
obtained,  the  plotter  sets  the  gun-arm  on  it  and  by  means  of  the 
indicator  determines  the  zone,  range,  and  elevation  of  the  target. 
The  operator  reads  the  straight  azimuth  from  the  gun-azimuth 
scale  and  gets  the  zone  and  elevation  from  the  plotter.  He  then 
sets  the  elevation  scde-pointer  at  the  given  elevation,  turns  crank 
moving  small  azimuth  pointer  to  the  azimuth  he  obtained  from 
gun-arm  scale;  then  by  referring  to  the  large  azimuth  scale- 
pointer  he  reads  the  corrected  gun-azimuth,  which  he  sends  to 
the  pits  together  with  zone  and  elevation.  Should  it  become 
necessary  to  make  a  correction  for  drift,  turn  the  deflection-scale 
knob,  either  to  right  or  left,  as  the  case  may  be,  as  3  =  normal. 
(See  Fig.  83.) 

Note. — This  apparatus  depends  upon  the  fact  that  the  drift 
is  the  same  for  the  same  elevation  in  every  zone  except  the  eighth. 
In  this  zone  the  instrument  cannot  be  used  as  now  constructed. 

WARSHIPS. 

Q.  State  the  general  appearance,  average  length,  beam,  draft, 
speed,  tonnage,  thickness  of  belt  and  deck  armor  of  battleships, 
armored  cruisers,  protected  cruisers,  torpedo-boat  destroyers,  and 
torpedo  boats. 

A.  See  Table  "A." 

Q.  Point  from  Figs.  84  and  85  the  following : 
Sloop.  Gunboat. 

Schooner.  Protected  cruiser. 

Ship.  Armored  cruiser. 

Bark.  Battleship. 

Barkentine.  Torpedo-boat  destroyer. 

Brig.  Torpedo  boat. 

Brigantine.  Submarine. 

Steam  yacht.  Monitor. 

Revenue  cutter. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


156 


THE  GUNNER'S   E  XAMINER. 
TABLE  A. — TABLE  OF  WARSHIP  CHARACTERISTICS. 


Characteristics. 

Battleships. 

Armored 
Cruisers. 

Protected 
Cruisers. 

Torpedo 
Boat 
Destroy- 
ers. 

Torpedo 
Boats 

General  Appearance. 

Large,    mas- 
sive     ap- 
pearance, 
low      free- 
board  , 
large,    tur- 
rets, heavy 
guns,    hea- 
vy   armor, 
moderate 
speed. 

High  free- 
board, fine 
lines,  fairly 
heavy  guns 
and  tur- 
rets, great 
length  as 
compared 
to  beam, 
high  speed. 

High     free- 
fa  o  a  r  d  , 
moderate 
size,  very 
fine  lines, 
light     ar- 
mament, 
narrow 
beam. 

Very  long, 
n  a  r  ro  w 
beam, 
high 
bow  low 
free- 
board, 
many 
smoke- 
stacks. 

Small  size, 
long, 
narrow, 
not    as 
many 
smoke- 
stacks 
as  a  de- 
stroyer. 

Average  length  

400  feet 

500  feet 

3  ^o  feet 

250  feet 

17^  feet 

Average  beam 

?<;  feet 

67  feet 

TO  feet 

Average  draft 

20  feet 

28  feet 

22  feet 

Average  speed 

17  knots 

21  knots 

22  knots 

•21  knots 

28  knots 

Average  tonnage               .    . 

15,000  tons 

11,000  tons 

5000  tons 

350  tons 

200  tons 

Aver,  thickness,  belt  armor 
Aver.  thickness,deck  armor 

13  inches 
3  inches 

5  inches 
3^  inches 

none 
Protective 
deck  2  ins 

Q.  What  vessels  are  unarmored? 

A.  Gunboats,  torpedo-boats  and  destroyers. 

Q.  What  is  the  best  part  of  a  ship  to  attack  at  long  range? 

A.  The  decks. 

Q.  What  part  should  rapid-fire  guns  attack  at  short  range  ? 

A.  Sides,  ends,  and  small  turrets,  and  guns  protected  only 
with  shields.  These  rules,  however,  may  vary  with  height  of 
battery,  form  of  attack,  and  class  of  ships  attacking. 

Q.  How  are  ships  of  the  U.  S.  Navy  distinguished,  knowing 
their  names?  (See  Fig.  86.) 

A.  Battle-ships  are  generally  named  after  States  (except  the 
Kearsarge),  cruisers  after  large  cities,  gunboats  after  historical 
cities  as  a  rule,  coast-defense  monitors  have  Indian  names,  tor- 
pedo-boats and  torpedo-boat  destroyers  are  named  after  heroes 
of  wars.  (The  above  rules  have  a  few  exceptions.) 

Q.  From  the  silhouettes  on  Fig.  86,  Ships  of  the  U.  S.  Navy, 
find  a  battle-ship,  a  high-speed  cruiser,  a  gunboat,  a  coast-defense 
monitor. 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


n 


1 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


159 


|r=  ro 


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S  2 
3  £ 

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i6o 


THE  GUNNER'S  EXAMINER. 


A.  Signal  numbers  20,  30,  23,  6. 

Q.  Find  from  Figs.  86  to  93  inclusive,  a  battle-ship,  cruiser, 
monitor,  and  gunboat  of  the  navies  of  Germany,  France,  England, 
Japan,  and  Russia. 


1000 

2000 

3000 

•S  4000 

>  5000 

S)6000 

J  7000 

8000 

9000 

10000 


1      2 


Thickness  of  Armor— Inches 
3     4     5     6     7     8     9     10  1 1   1 2  1 3  14  1 5  16 


*  Model  1900 


10          12*   12t   Caliber  of  Gun-Inches 
by  U.S.  Navy  formula  far  KjC..-Armor 

FIG.  87. 


Q.  What  thickness  of  Krupp  cemented  armor  will  a  six-inch 
gun  penetrate  at  5000  yards?  An  eight-inch  gun?  A  ten-inch 
gun?  A  twelve-inch  gun,  model  1895?  A  twelve-inch,  model 
1900? 

A.  Six-inch  penetrates  3  inches;  eight-inch,  5  inches;  ten- 
inch,  7  inches;  twelve-inch  '95,  10  inches;  twelve-inch  1900,  12 
inches.  (See  Armor-attack  Sheet,  Fig.  86.) 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


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CODE  FLAGS  AND  PENNANTS 
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Signal 


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Winds  Winds  Winds  Winds  Signal 

Flags  8  feet  square. Pennants  5  feet  hoist,  1 2  feet  fly 

U.S.  WEATHER-BUREAU  SIGNALS 


Clearer  Rain  or  Local  Rain        Temperature       Cold 

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FOR    TORPEDO-COMPANY   GUNNERS.        Z69 
EXAMINATION   FOR  TORPEDO-COMPANY   GUNNERS. 

SECOND-CLASS   GUNNERS. 

Ammunition,  Nomenclature,  and  Service  of  Piece. 

Note. — In  the  following  series  of  questions  and  answers  the 
new  and  adopted  system  only  is  included. 

Q.  What  guns  are  usually  assigned  to  torpedo  companies? 

A.  R.  F.  guns,  principally  3-inch. 

Q.  Give  a  rough  outline  of  the  general  operation  of  the  system 
of  submarine  mines. 

A.  A  submarine  mine  is  a  ball-shaped  iron  case  filled  with 
high  explosive.  Several  of  these  are  planted  across  a  channel  and 
held  below  the  surface  of  the  water  by  heavy  anchors.  From 
each  mine  is  run  a  single-core  cable.  All  these  cables  join  the 
wires  of  a  multiple-core  cable  which  runs  to  the  "mining  case- 
mate." In  this  building  are  electrical  devices  for  firing  the 
mine  either  when  it  is  struck  by  the  enemy's  ship  (called  "con- 
tact-firing"), or  at  the  mine-commander's  will  ("observation- 
firing").  This  firing  is  accomplished  by  sending  an  electric 
current  through  the  cable  to  the  mine.  Inside  the  mine  is  an 
electric  fuse.  The  return-circuit  is  by  ground.  (The  details  of 
electrical  and  engineering  features  and  wiring  are  not  required 
of  a  second-class  gunner.) 

Q.  What  ammunition  is  used  in  the  3-inch  R.  F.  gun  ? 

A.  A  cartridge  case  of  solid  drawn  brass  about  23  inches  long 
containing  a  powder  charge  in  the  base  of  5  pounds  of  smokeless 
and  a  projectile  weighing  15  pounds  in  the  top.  Armor-piercing 
shell  and  shrapnel  are  also  used.  The  saluting  charge  weight, 
2  pounds. 

Q.  What  primer  is  used  ? 

A.  The  Frankford  Arsenal   no-grain  igniting.     (See  No.  2, 

Fig.  97-) 

Q.  Name  the  principal  parts  of  this  primer. 


170 


THE  GUNNER'S  EXAMINER. 


IGNITING  PRIMERS 

FOR 
R.F.GUNS 

NO.1 
IGNITING  PRIMER  FOR  FIXED 

AMMUNITIOJSU— Vent  Closing  Disk,  Paper 
-Body,  Brass 
Obturating  Cup,  Brass 
turating  Valve,  B.rass 
rimer  Charge 


End  Closing  Wad,Paper 


NO.2 

10  GRAIN  IGNITIN: 
PRIMER 


ompressed 
Powder  Charge 


N0.3 

20  GRAIN  IGNITING 
PRIMER 


Compressed 
Powder  Charge 


FIG.  97. 


EXAMINATION  FOR    TORPEDO  COMPANY   GUNNERS.        171 

A.  Body,  obturating-cup,  vent-closing  disc,  primer  charge, 
end-closing  wad.  (See  No.  2,  Fig.  97.) 

Note. — The  following  data  is  given  for  general  information 
only : 

Weight  of  the  piece,  1722  pounds.  Length,  154.5  inches. 
Length  of  bore,  50  calibers.  Number  of  grooves,  24.  Twist  of 
rifling,  i  in  50  calibers  at  the  breech  an  dincreasing  to  i  in  25 
at  the  muzzle.  Kind  of  powder,  smokeless.  Weight  of  charge, 
5  pounds.  Weight  of  projectile,  15  pounds.  Muzzle  velocity, 
2600  feet  per  second.  Muzzle  energy,  702.9  foot-tons.  Penetra- 
tion in  steel,  at  the  muzzle  5.37  inches;  at  1000  yards,  3.82  inches; 
at  2000  yards,  2.72  inches;  at  3000  yards,  1.94  inches. 

Q.  Point  out  the  following  parts  of  the  breech-block: 
Block.  Locking  spring.  Slotted  sectors. 

Carrier  plate.  Lever  handle.  Extractor. 

Carrier  plate  ring.          Threaded  sectors.         Firing  pin. 
A.  See  Figs.  17  and  19. 
Q.  What  acts  as  the  gas  check? 

Q.  How  should  a  3-inch  R.  F.  breech-block  be  cared  for — 
kind  of  oil,  etc. 

A.  Same  as  for  any  other  heavy  gun.     (See  first  part  of  book.) 
Q.  Describe  how  the  extractor  and  firing  pin  work. 
A.  (This  will  have  to  be  done  at  the  gun.) 
Q.  Describe  the  action  of  the  lever  handle. 
A.  (Do  this  at  the  gun.) 

Q.  Point  out  the  following  parts  of  the  gun  and  mount  (mask- 
ing parapet  mount) : 

Outer  base.  Traversing  clamp. 

Inner  base.  Elevating  clamp. 

Counterweights.  Range  drum. 

Recoil-cylinder.  Cradle. 

Piston-rod.  Elevating  gear. 

Pivot.  Sight. 

Pivot  yoke.  Night  Sights. 

Trunnions.  Ratchet  lever. 


172  THE  GUNNER'S  EXAMINER. 

Lever  pawl.  Muzzle. 

Ratchet-wheel  pawl.  Breech. 

Pivot  socket  and  clamp.  Bore. 

Shield.  Chamber. 

A.  See  Figs.  17  and  19. 

Q.  How  are  rapid-fire  guns  cared  for  and  kept  in  working 

order  ? 

A.  Same  as  the  12",  10",  8",  6",  etc.  (Given  under  heading 
for  second-class  gunners,  Gun-companies.) 

Q.  How  many  men  constitute  a  gun  detachment  for  the 
3-inch  R.  F.  gun  (masking  parapet  mount)  and  give  the  posts  of 
each? 

A.  Chief  of  detachment,  gun-pointer,  and  5  men. 

POSTS. 

Chief  of  detachment,  2  yards  to  the  right  of  the  carriage, 

facing  it. 
Gun-pointer,  immediately  in  rear  of  the  shoulder  piece, 

facing  to  the  front. 

No.  i,  2  feet  to  the  right  and  rear  of  the  breech  facing  it. 
No.  2,  2  feet  to  the  left  and  rear  of  the  breech  facing  it. 
No.  3,  on  the  right  of  the  gun,  near  the  elevating  clamp, 

facing  to  the  front. 

No.  4,  3  feet  in  rear  of  the  breech  facing  it. 
No.  5,  near  the  ammunition  recess,  facing  the  gun. 
The  posts  of  the  gun  detachment  as  given  above  are  for  in- 
spection and  preparatory  to  the  service  of  the  gun. 

The  men  resume  their  posts  on  the  completion  of  any  duty 
requiring  them  elsewhere. 

The  chief  of  detachment  and  gun-pointer  go  wherever  their 
presence  is  necessary. 

Q.  Give  the  duties  of  the  gun  commander,  chief  of  detach- 
ment, and  gun-pointer. 

A.  The  gun  commander  indicates  the  target,  repeats  the  com- 
mands " Commence  firing"  and  " Cease  firing,"  announces  the 


EXAMINATION  FOR    TORPEDO-COMPANY   GUNNERS.         173 

kind  of  projectile  to  be  used,  the  order  of  fire,  and,  in  restricted 
fire,  the  number  of  shots  and  the  firing  interval.  He  is  responsible 
to  the  battery  commander  for  the  condition  of  the  material  and 
the  efficiency  of  the  personnel  of  his  command,  sees  that  the  guns, 
magazines,  equipments,  and  implements  are  properly  secured 
after  the  day's  drill. 

The  chief  of  detachment  is  responsible  that  the  gunner  identifies 
the  target.  He  is  particularly  charged  with  seeing  that  his  piece 
is  properly  loaded  and  that  the  precautions  for  safety  in  case  of 
misfires  are  carried  out.  At  the  command  "Cease  firing"  he 
will  cause  the  breech  to  be  opened. 

The  gun-pointer  is  responsible  for  the  proper  regulation  of  the 
current  for  the  lights  of  the  night  sights.  He  adjusts  the  sight 
in  its  seat  and  sets  the  elevation  and  the  deflection  scales  for  the 
indicated  range  and  deflection.  He  aims  the  gun  and  fires  as 
soon  after  the  command  " Ready"  as  the  piece  is  aimed.  He 
will  observe  the  splash  of  his  shots  if  possible  and  when  necessary 
make  the  proper  correction  on  his  sight.  In  connection  with  the 
gun  commander  he  determines  the  deflection  correction  for  travel 
of  target,  using  the  deflection  scale  for  the  purpose. 

Q.  Give  the  duties  of  the  members  of  the  detachment  for 
loading  and  firing. 

A.  The  chief  of  detachment  indicates  the  target  and  range  and 
commands:  i.  No.  — ,  2.  With  (such  projectile),  3.  Commence 
tiring  (or,  so  many  rounds,  commence  firing) . 

He  repeats  the  command  cease  firing. 

After  the  first  round  the  projectile  is  named  only  when  a 
different  kind  is  ordered  and  the  gun  is  loaded  without  command 
immediately  after  it  is  fired. 

The  gun-pointer,  when  the  gun  has  the  proper  elevation, 
commands  and  signals  clamp.  He  fires  by  lanyard  and  in 
simulated  firing  calls  out  fire  when  he  pulls  the  lanyard,  as  a  signal 
to  load. 

No.  i  opens  the  breech,  closes  it  as  soon  as  the  cartridge 
is  inserted,  and  calls  out  ready  as  soon  as  he  is  clear  of  the  recoil. 


174  THE  GUNNER'S  EXAMINER. 

(If  there  is  any  difficulty  in  opening  or  closing  the  breech,  he 
examines  the  threads  of  the  breech-block,  wipes  off  any  dirt  found, 
and  oils  the  mechanism.) 

No.  2  receives  a  round  of  ammunition  from  No.  5  and  inserts 
it  in  the  chamber. 

(If  there  is  difficulty  in  opening  or  closing  the  breech,  he 
examines  the  threads  of  the  breech  recess,  wipes  off  any  dirt 
found,  and  oils  the  threads  if  they  become  dry.) 

No.  3  clamps  the  gun  in  elevation  at  the  gun-pointer's  com- 
mand and  unclamps  immediately  after  the  gun  is  fired. 

No.  4  receives  the  empty  cartridge  case  as  it  is  ejected  and 
lays  it  aside. 

No.  5  brings  a  round  of  ammunition  of  the  designated  kind 
from  the  recess  and  passes  it  to  No.  2. 


MATERIAL  AND  DUTIES  OF  THE  LOADING-ROOM. 

(Except  electrical  principles  involved.) 

Q.  What  apparatus  is  used  in  making  a  Turk's  head? 

A.  A  navy  knife  and  tool-box  "D"  is  required.  Besides  the 
tools  the  box  should  be  equipped  with  a  supply  of  Turk's  head 
collars  and  marline. 

Q.  What  is  used  in  making  a  telegraph-joint? 

A.  A  pair  of  pliers,  navy  knife,  and,  where  insulation  is 
desired,  okonite  tape. 

Q.  What  is  used  in  making  a  joint  to  be  used  under  water  ? 

A.  A  navy  knife,  tool-box  "D,"  junction-boxes  in  which  to 
clamp  the  Turk's  heads,  and  the  material  for  making  okonite 
joints  or  the  cores.  These  materials  are,  okonite  tape,  cement, 
Manson  tape  and  tin-foil.  A  torch  is  needed  for  vulcanizing 
the  joint.  Brass  jointers  are  sometimes  used  in  making  the 
joints. 

Q.  Point  out  all  the  parts  of  an  assembled  mine. 

A.  See  Fig.  98. 


EXAMINATION  FOR    TORPEDO-COMPANY   GUNNERS.         if 3 


AN  ASSEMBLED  MINE 


Planting  Buoy 

Distribution  Box  Buoy 
lanting  Buoy  Raising  Rope 


Raising  Rope- 

Single  Conductor  Cables 
to  other  Mines 


FIG.  98. 


176  THE  GUNNER'S  EXAMINER. 

Q.  Point  out  the  following  parts  of  a  compound  plug:  circuit- 
closers;  transformer;  loading-wire;  fuse-wires;  fuses;  fuse-can; 
bursting-charge;  set-screw  for  fuse-can;  lead  or  graphite  gasket 
for  same;  rubber  packing;  brass  washers;  fuse-can  cap;  lower 
tube  set-screw;  gland;  lower  tube;  plug  proper;  loading- wire. 

Q.  Name  some  of  the  duties  in  the  loading-room. 

A.  Loading  mines  with  explosives;  assembling  them  complete 
to  the  single-core  cable;  preparing  compound  plugs,  cables,  and 
raising-ropes;  in  other  words,  preparing  a  mine  for  planting  in 
the  harbor,  except  attaching  the  anchor  and  mooring-rope. 

Q.  Make  a  telegraph-joint. 

A.  See  Figs.  99  and  100. 

Q.  Make  a  Turk's  head. 

A.  See  Fig.  101.  Trim  the  ends  square:  15  inches  from  it 
place  a  wrapping  of  a  few  turns  of  marline  overlapping  each  other 
and  secured  by  a  square  knot.  Slip  on  the  collar,  flat  side  against 
the  stop  of  the  marline;  bend  the  iron  wires  back  over  the  collar 
and  cut  off  4  inches  from  one  and  6  inches  from  the  next,  alter- 
nately. Bend  the  wires  with  the  pliers  as  so  to  closely  fit  and 
crimp  the  collar.  Beginning  at  the  Turk's  head,  wrap  closely 
with  marline  so  as  to  bind  the  wires  to  the  cable.  The  jute 
covering  and  serving  maybe  bent  back  over  the  wires,  or  it  may  be 
cut  off :  in  cutting  turn  the  edge  of  the  knife  away  from  the  cable. 

Q.  Make  a  taped  joint,  place  it  in  salt  water  for  30  minutes 
and  test. 

A.  i°  Bare  the  two  ends  of  wire  about  f  inch. 
2°  Join  by  brass  jointer,  then  crimp. 
3°  Cover  with  rubber  cement. 
4°  Wrap  with  tape,  about  five  or  six  layers. 
5°  Wrap  with  tin-foil. 
6°  Wrap  with  Manson  tape. 

7°  Vulcanize  for  about  30  seconds  and  unwrap  tin-foil  and 
Manson  tape  and  rewrap  with  new  Manson  tape. 

Q.  How  is  a  taped  joint  vulcanized  when  in  the  "distribution- 
box  boat''? 


EXAMINATION  OF  FIRST-CLASS  GUNNERS. 


TELEGRAPH-JOINT 
MADE  WITHOUT   BRASS  JOINER. 


TURK'S 
HEAD 


FIG. 


TELEGRAPH  JOINT  WITH   BRASS  JOINER, 


FIG.  ioo. 


i78 


THE  GUNNER'S  EXAMINER. 


A.  By  tying  a  piece  of  waste  soaked  in  kerosene  to  a  wire 
lighting,  and  using  this  as  a  torch  for  heating  the  joint. 
Q.  Explain  the  method  of  preparing  a  compound  plug. 


Galvanometer 


Scale 


FIG.  102. 


A.  This  will  have  to  be  learned  by  practice  and  constant 
instruction  at  the  loading-room. 

Note. — The  transformer,  fuse,  can,  etc.,  on  the  compound 
plug  are  still  in  a  state  of  experimentation  and  no  method  for  the 
assembling  of  the  latest  design  has  been  adopted  as  yet. 


EXAMINATION  FOR    TORPEDO-COMPANY  GUNNERS.        l79 

Q.  How  do  you  test  the  transformer  ? 

A.  With  a  circuit  detector  or  galvanometer  and  a  dry  cell, 
as  shown  in  figure. 

Note. — In  case  of  a  break  in  the  coil,  Fig.  102,  there  would  be 
no  current  flowing  in  galvanometer  and  no  deflection  of  the  needle 
would  be  indicated. 

The  wires  that  should  show  closed  circuit  are  the  two  red  wires 
and  the  black  wire  and  transformer  case.  Those  that  should  be 
open  are  the  black,  and  either  red  wire.  (See  Fig.  102.) 

Q.  How  are  fuses  tested  ? 

A.  With  a  dry  cell  and  a  circuit  detector.  A  closed-circuit 
test  is  all  that  is  necessary.  This  should  always  be  done  under 
the  supervision  of  an  experienced  electrician. 

Q.  What  apparatus  is  used  in  preparing  a  compound  plug 
complete  ? 

A.  Bench  vise,  S-wrench,  large  monkey  wrench,  screw  driver, 
small  pliers,  navy  knife,  loading  wire,  cotton-braided  wire, 
priming  charge,  fuses,  rubber  packings,  brass  washers,  followers, 
lead  washers,  set  screws,  red  lead  or  ruberine,  circuit  detector, 
brass  jointers,  rubber  tape. 

Q.  What  is  the  method  of  numbering  mines? 

A.  Facing  in  the  direction  of  the  expected  approach  of  the 
enemy's  ships,  mines  are  numbered  from  left  to  right,  beginning 
with  No.  i. 

Q.  How  are  groups  numbered  ? 

A.  In  the  same  manner.  No.  i  group  on  the  left,  No.  2  next 
toward  the  right,  etc. 

Q.  How  are  the  mooring-ropes  prepared,  and  what  are  the 
rules  for  length  of  mine  cables  and  of  mooring-ropes  ? 

A.  The  mooring-cables  are  cut  off  with  square  ends  and  the 
ends  passed  through  the  holes  in  the  mooring-sockets.  The 
strand  and  wires  are  untwisted  and  spread  out  for  a  length  equal  to 
the  length  of  the  socket-hole.  The  rope  is  then  pulled  back  until 
the  loose  ends  are  about  flush  with  the  top  edge  of  the  hole ;  a  piece 
of  marline  is  tied  about  the  rope  below  the  socket.  If  necessary 


i8o  THE  GUNNER'S  EXAMINER. 

to  hold  the  socket  a  piece  of  burlap  may  be  wrapped  around 
below  the  socket  and  a  fold  allowed  to  fall  over  the  hand.  Gener- 
ally means  can  be  found  to  set  the  socket  upright  while  pouring 
full  of  alloy.  Great  care  must  be  taken  to  see  that  there  is  no 
water  or  surplus  oil  on  the  socket  or  mooring-rope  before  pour- 
ing the  alloy.  (Nine  parts  lead,  i  part  antimony.) 

Mines  are  planted  with  a  submergence  of  5  feet  below  mean 
low  water. 

Where  ordinary  anchors  are  used  the  mooring-ropes  must  be 
prepared  for  depths  obtained  by  sounding.  If  sockets  are  used, 
the  ropes  for  No.  32  cases  are  but  10  feet  less  than  the  ascertained 
depths  at  mean  low  water.  This  allows  5  feet  for  submergence 
and  5  feet  for  mine,  mine  bail,  sockets,  shackles,  and  anchor. 
For  the  larger  mine  cases  an  additional  allowance  must  be  made 
for  the  length  of  the  cylindrical  part  of  the  case.  Finally  each 
mooring-rope  is  tagged  at  each  end  with  the  number  of  the  corre- 
sponding mine. 

Mine  cables  are  cut  to  the  following  lengths,  plus  twice  the 
approximate  depth  of  the  water: 

Feet.  Feet. 

No.    i 1425  No.  ii 425 

No.    2 1225  No.  12 475 

No.    3 1025  No.  13 525 

No.    4 825  No.  14 625 

No.    5 725  No.  15 725 

No.    6 625  No.  16 825 

No.    7 525  No.  17 1025 

No.    8 475  No.  1 8 1225 

No.    9 425  No.  19 1425 

No.  10 375 

Each  end  of  each  cable  is  tagged  with  the  number  of  the  corre- 
sponding mine. 


EXAMINATION  FOR    TORPEDO-COMPANY  GUNNERS.          18 r 
MATERIAL  FOR  AND  DUTIES  ON  THE  WATER. 

Q.  What  apparatus  is  taken  out  on  the  distribution-box 
boat? 

A.  One  distribution-box,  i  buoy  for  same,  i  mooring-rope  for 
attaching  buoy  to  distribution-box,  i  anchor  sufficiently  heavy 
to  hold  distribution-box  boat,  i  anchor  buoy  (keg),  and  rope  for 
same,  2  anchor  shackles  (i  for  anchor  and  i  for  box),  i  pair 
field  glasses,  alcohol,  2  alcohol  lamps,  cable  tags,  Turk's  head, 
collars,  cotton  waste,  2  files,  2  hammers,  2  heavy  lines,  knives, 
marline,  2  marline  spikes,  i  megaphone,  2  monkey  wrenches, 
2  pliers,  protective  tape,  rubber  cement,  rubber  tape,  2  scissors, 
tin-foil, -telephone,  brass  connectors,  lashings. 

The  planter  may  locate  the  distribution-box  bo"at  anchor,  and 
in  that  case  it,  together  with  its  buoy,  would  not  be  taken  out 
in  the  distribution-box  boat. 

Q.  How  and  in  what  way  are  the  cores  of  cable  numbered  ? 

A.  They  are  numbered  by  the  non-commissioned  officer  in 
charge  of  the  boat,  who  establishes  communication  with  the  case- 
mate, using  the  boat  telephone,  and  working  under  the  instruc- 
tions of  the  casemate  electrician. 

Nos.  i,  13,  and  19  are  easily  selected  by  means  of  their  special 
marking;  No.  19  is  the  center  core;  No.  13  is  the  marked  core 
in  the  inner  row  of  six;  and  No.  i  is  the  marked  core  in  the  outer 
row  of  twelve. 

In  the  seven-cored  cable  there  are  no  marked  cores,  the  cores 
being  numbered  under  the  instructions  of  the  casemate  elec- 
trician. 

Q.  How  is  multiple  cable  laid  ? 

A.  It  is  transported  to  the  planter  by  tramway,  hoisted  by 
steam-derrick  to  the  forward  jacks;  it  is  then  joined  to  the  "shore 
ends"  of  the  cable;  the  planter  then  steams  to  the  distribution- 
box  buoy  and  passes  the  end  of  the  cable  to  the  distribution 
launch,  where  a  Turk's  head  is  made  and  all  is  ready  to  receive 
the  single-core  cables  for  planting. 


1 8a  THE  GUNNER'S  EXAMINER. 

PLANTING  OF  MINES. 

Q.  How  are  single-core  cables  prepared  ? 
A.  i°  If  the  single-core  cable  has  not  been  cut  and  coiled  in 
loading-room,  place  reel  on  jacks,   cut   20  feet  off 
the  end,  unreel  to  lengths  given  previously,  cut  and 
tag  with  mine  number. 

2°  Carry  cable  No.  19  on  port  side  to  after  deck,  keeping 
tagged  end  forward  and  coil  in  figure  eight,  keeping 
tagged  end  on  bottom. 

3°  Make  Turk's  head  on  each  end,  first  slipping  tagged 
end  through  a  mine  cap. 

4°  Continue  the  operation  above  in  the  following  order: 
Nos.  i  to  9  starboard  side. 
Nos.  10  to  19  port  side. 

Q.  Describe  how  to  place  mines  aboard  and  to  attach  to 
cables  preparatory  to  being  planted. 

A.  i°  Place  mine  buoys,  anchors,  mooring-ropes,  raising- 
ropes,  shackles,  sister  hooks,  etc.,  aboard  forward 
and  in  convenient  places. 

2°  Place  loaded  mines  aboard  last,  nine  on  starboard  and 
ten  on  port. 

3°  Cut  to  proper  length  the  loading  wire,  make  a  tapped 
joint  with  S.  C.  conductor  with  Turk's  head,  pre- 
viously prepared  through  mine  cap. 

4°  Fasten  mine  cap  on  mine,  lash  cables  to  bales,  shackle 
mooring-rope  to  mine,  and  anchor,  lash  mooring- 
rope  to  mine  cable  every  5  feet  (not  done  if  auto- 
matic anchor  is  used). 

5°  Cut  raising-ropes  50  feet  plus  depth  of  water  and 
attach  one  end  to  anchor  by  anchor  knot,  the  other 
end  to  mine  cable  by  two  half  hitches  and  a  serving 
of  marline,  secure  at  a  few  other  points. 

6°  Attach  about  60  feet  small  rope  to  mine  buoys  and 
mark  this  rope  every  5  feet,  slip  free  end  through 


EXAMINATION  FOR   TORPEDO-COMPANY  GUNNERS.         183 

maneuvering  ring,  and  tie  to  buoy.  (The  mines, 
anchors,  cables,  raising-ropes,  and  mine  buoys  are 
now  ready  to  be  planted.) 

Q.  Explain  how  to  sling  the  mine  and  anchor,  and  prepare 
it  to  "let  go." 

A.  i°  Mouse   upper   hooks   of   differential   blocks   and   lash 

well  with  marline  the  tripping  hooks. 
2°  Sling  the  anchor  to  the  tripping  hook  on  the  differential 
block  of  the  forward  davit,  swing  clear  of  rail,  and 
lower  close  to  water. 

3°  Perform  similar  operation  with  mine  from  after  davit. 
Q.  Describe  the  method  of  planting. 

A.  The  planter  now  moves  to  the  distribution-box  boat,  the 
latter  to  the  port,  No.  10  cable  is  passed  to  the  same,  planter 
now  moves  to  No.  10  buoy,  and  when  mine  is  abreast,  the  com- 
mand "let  go"  is  given. 

The  tripping  hook  of  the  mine  is  released  first,  and  that  of 
the  anchor  immediately  after.  The  planter  now  circles  to  star- 
bo  rd,  passes  to  the  rear,  and  comes  up  to  the  distribution-box 
boat  to  the  starboard.  No.  9  is  now  passed,  and  planter  moves 
forward  to  the  position  of  this  mine,  plants  it,  and  returns  to 
distribution-box  boat  to  repeat  the  operation  till  the  group  is 
planted. 

CAUTIONS  TO  BE  OBSERVED. 

Men  operating  tripping  hooks  keep  their  feet  free  from  all 
cable.  Men  on  after  deck  must  keep  entirely  free  of  all  cable 
while  being  spent  when  planter  is  passing  from  distribution-box 
boat  to  mine  buoy. 

If  dynamite  is  used  as  explosive  all  mines  should  be  covered 
with  paulines  or  burlap  to  protect  them  from  the  direct  rays  of 
the  sun. 

Q.  Name  the  apparatus  on  the  boat  used  in  planting  mines. 

A.  Derricks,  catheads,  snatch-blocks,  steam-winches,  in- 
sulated cable,  cable-drum  frames,  circuit  detector,  boat-hooks, 


184  THE   GUNNER'S  EXAMINER. 

sounding-lines  graduated  to  feet,  davits,  differential  blocks, 
mooring-ropes,  raising-ropes,  buoyant  mines  and  anchors,  shackles 
and  extra  split  pins  for  same,  lashing-rope,  alcohol,  2  alochol 
lamps,  i  cable  cutter,  cable  tags,  Turk's  head,  collars,  cotton 
waste,  4  files,  4  hammers,  6  heaving-lines,  knives,  marline,  2 
marline  spikes,  i  megaphone,  2  monkey  wrenches,  4  pliers, 
protective  tape,  rope,  rubber  cement,  rubber  tape,  2  scissors, 
i  set  of  stencil  numbers,  tin-foil,  and  a  measuring  line  which  has 
marks  every  100  feet,  with  double  marks  at  300  and  600  feet. 

Q.  Give  a  method  for  marking  the  positions  at  which  mines  are 
to  be  planted. 

A.  The  distribution-box  is  located  first,  a  buoy  and  anchor 
being  used  as  the  mark.  The  center  point  of  the  group  is  located 
next,  then  the  two  ends  of  the  group.  The  launch  is  directed 
over  the  spot  selected  from  the  map.  for  the  distribution-point 
by  means  of  base-end  instruments  at  the  primary  and  secondary 
stations  (these  two  instruments  being  set  at  the  azimuth  of  the 
selected  spot),  and  by  signals  from  these  stations  the  launch  drops 
the  anchor  and  buoy  when  it  is  at  the  intersection  of  the  vertical 
cross-wires  of  each  instrument.  The  launch  marks  the  center 
of  the  group  by  moving  approximately  perpendicular  to  the  line 
of  mines  to  the  desired  distance.  The  line  of  mines  is  then 
determined  by  taking  bearings  and  objects  on  shore  (previously 
determined  from  the  map)  or  by  a  similar  method  to  that  of  locating 
the  distribution-box  buoy.  Small  planting-buoys  are  used  for 
this  purpose.  The  distribution -box  buoy  is  usually  a  large  keg 
or  vinegar-barrel. 

Q.  How  are  soundings  made? 

A.  By  starting  from  either  end  of  the  "located  group"  and 
making  a  sounding  at  every  100  feet. 

SMALL  BOAT  DRILL. 

Q.  Explain  how  a  small  boat  used  for  marking  and  locating 
is  managed,  and  give  the  commands  necessary. 


EXAMINATION  OF   TORPEDO-COMPANY  GUNNERS.         185 

A.  Upon  leaving  wharf,  "Shove  off!"  performed  by  designated 
man. 

To  raise  oars  preliminary  to  rowing:  "Up  oars!"  all  oars 
being  held  vertically,  opposite  rowlocks,  blades  athwart  boat. 

To  lower  oars  into  the  water :  "  Let  fall ! " ;  all  oars  are  dropped 
easily  into  the  water,  without  splashing,  and  quickly  adjusted 
into  the  rowlocks,  and  then  held  in  position  of  "Oars!"  (See 
below.) 

To  move  the  boat  forward :  "  Stand  by  to  give  way  together! — • 
GIVE  WAY  TOGETHER!"  the  boat  being  propelled  forward  at  the 
latter  command,  all  the  men  taking  a  slow  uniform  stroke,  being 
guided  by  No.  i,  feathering  their  oars  as  they  come  out  of  the 
water  and  move  forward. 

To  cease  rowing  temporarily:  "Oars!";  at  this  command  the 
oars  are  raised  out  of  the  water  to  a  horizontal  position,  blades 
parallel  with  the  surface  of  the  water. 

To  rest  without  taking  oars  from  rowlocks:  "In  oars,"  when 
oars  are  drawn  in  and  placed  with  handles  under  gunwales  on 
opposite  side  of  boat  from  rowlocks. 

To  move  backward  a  short  distance:  "Back  water!"  executed 
opposite  to  "Give  way  together!" 

To  stop  boat:  "Hold  water!";  the  oars  are  held  rigidly  in 
the  water,  blades  vertical. 

To  stop  boat  quickly,  as  if  running  on  a  rock:  "About  face! 
hold!"  when  the  oarsmen  turn  about  and  hold  blade  in  water, 
stopping  momentum  of  boat. 

To  turn  to  port:  "Pull  starboard,  back  port!"  (To  turn  to 
starboard,  the  opposite). 

To  make  a  landing:  "In  bow!";  the  bow  oar  is  raised  verti- 
cally, then  lowered  into  its  place  in  the  boat,  and  the  bow  man 
takes  the  boat-hook  and  guides  boat  gently  into  its  place. 

To  cease  rowing:  "Way  enough!";  the  oars  are  raised  verti- 
cally, shoved  properly  in  place. 


i86  THE  GUNNER'S  EXAMINER  . 


CORDAGE. 

Q.  Name  the  important  knots  used  in  mine-work. 

A.  Anchor-knot  or  fisherman's  bend,  square  knot,  clove-hitch, 
bowline,  stopper,  whipping,  and  short  splice.  (See  plate  of  knots 
for  gun-companies.^ 

THE  U.  S.  MAGAZINE  RIFLE. 

See  Examination  for  Second-class  Gunners,  for  Gun-com- 
panies. 

FIRST-CLASS  GUNNERS. 
CARE   AND   PRESERVATION   OF   MINE   MATERIAL. 

Q.  How  are  mine-cases  preserved  and  cared  for? 

A.  They  are  painted  light  gray  on  the  outside,  and  the  screw- 
threads  covered  with  a  mixture  of  lard-oil  and  white  lead  (4  parts 
of  tallow  to  i  white  lead).  They  are  also  either  painted  or 
covered  with  protective  material  on  the  inside.  They  are  then 
stored  on  suitable  racks  inside  a  "torpedo  storehouse." 

Q.  How  are  all  bearing  surfaces,  such  as  screw-threads,  pre- 
pared for  storage? 

A.  By  first  thoroughly  cleaning  them  with  brushes,  kerosene, 
waste,  etc.,  and  then  covering  with  the  above  mixture  of  white 
lead  and  tallow. 

Q.  How  is  the  motor-generator  cared  for? 

A.  Fill  all  oil-holes,  and  keep  all  parts  free  from  dust  and 
foreign  material;  see  that  all  connections  are  tight;  see  that  all 
brushes  are  in  good  condition,  and  replace  worn  ones  by  new 
ones.  Use  very  fine  sandpaper  for  slight  inequalities  of  the  com- 
mutator. 


EXAMINATION  OF   TORPEDO-COMPANY  GUNNERS. 


187 


Q.  How  are  the  mine-panel  and  the  switchboard  cared 
for? 

A.  See  that  all  bolts  to  busses  are  tight,  that  all  lamps  are 
screwed  home,  that  all  contacts  are  clean  and  free  from  gum  or 
dirt,  that  all  switches  work  properly  and  all  contacts  correctly 
made. 

Q.  How  should  electric  lights  be  cared  for? 

A.  They  should  be  kept  clean  and  polished.  Any  snap- 
switch  that  sparks  badly  should  be  replaced.  No  verdigris  should 
be  allowed  to  accumulate  on  any  brass  fittings.  When  a  lamp 
becomes  dull  or  black  inside,  a  new  one  should  replace  it.  When 
any  fuse  is  blown  out,  new  ones  should  be  put  in.  (Never  use 
copper  wire  as  a  substitute  for  a  fuse.) 

Q.  How  should  transformers  be  cared  for? 

A.  Simply  kept  clean  and  in  a  dry  place.  They  should  be 
tested  with  a  circuit-detector  once  in  a  while. 

Q.  How  is  the  charging-generator  cared  for? 

A.  Keep  free  from  dirt  or  rust,  fill  all  oil-holes,  clean  the 
commutator  with  a  dry  rag,  keep  the  brushes  set  so  as  to  make 
good  contact,  and  when  not  in  use  cover  with  a  rubber  paulin. 

Q.  How  is  the  oil-engine  cared  for? 

A.  The  oil-engine  should  be  kept  clean  and  nicely  painted, 
all  oil-holes  filled,  the  water-tank  filled  and  free  from  mud  and 
sediment,  the  vaporizer  examined  from  time  to  time  and  kept  free 
from  packed  carbon,  the  piston  clean  and  well  oiled,  the  poppet- 
valves  tight  and  free  fram  any  clogging  material,  the  starting- 
torch  clean  and  free  from  soot. 

Q.  When  putting  a  piece  of  machinery  out  of  commission  what 
is  done  ? 

A.  All  bearing  surfaces  are  exposed,  cleaned,  and  covered  with 
white  lead  and  lard-oil  or  a  similar  substitute  preservative.  All 
small  loose  parts  are  removed,  covered  with  cosmic  wrapped  in 
burlap,  and  stored  under  cover.  The  machine  should  also  be 
housed. 

Q.  Name  some  of  the  principal  cleaning  materials. 

A.   Steel  scrapers,  button  and  wire  brushes,  waste,  pomade, 


i88  THE  GUNNER'S  EXAMINER 

sandpaper,  emery  and  crocus  cloth,  gasoline,  kerosene,  and 
alcohol. 

Q.  Name  some  preserving  materials. 

A.  Cosmic,  white  lead,  red  lead,  raw  linseed  oil,  turpentine, 
beef  tallow,  drier,  lamp  black,  pumice  stone,  varnish,  asphaltum 
varnish,  paint  brushes,  shellac,  graphite  paint  and  insulac. 

Q.  Name  some  uses  of  each. 

A.  Cosmic:  Covering  bright  parts  of  engines,  generators, 
motors,  etc.,  when  out  of  commission. 

White  Lead:  (4  pts.  W.  L.  to  i  of  tallow)  Used  on  screw- 
threads  of  mine  cases,  steel  threads,  compound  plugs,  bolts,  nuts, 
washers,  surfaces  of  flute  joints,  etc. 

Caution:  Never  use  this  on  a  joint  where  electrical  contact  is 
to  be  made. 

Red  Lead:  (100  pounds  red  lead  ground  in  linseed-oil  with 
5  gallons  raw  linseed  added.)  On  mine  cases  after  being  scraped. 
As  a  preliminary  coat  for  iron  surfaces  of  engines,  generators, 
etc. 

Raw  Linseed,  Turpentine,  Drier,  and  Lampblack,  for  making 
different  kinds  of  paint.  Turpentine  is  also  used  to  clean  brushes, 
etc. 

Tallow:  For  mixing  with  white  lead  to  form  a  preservative. 

Pumice-stone:  When  powdered  and  mixed  with  oil  is  used 
to  rub  down  surfaces,  as  the  first  coat  of  varnish  on  an  engine. 

Varnish:  As  a  finishing  coat  for  metal  and  wood  surfaces  not 
exposed  to  heat  or  water. 

Asphaltum  Varnish:  For  painting  anchors,  distribution-boxes, 
mooring-sockets,  shackles,  sister  hooks,  junction  boxes,  iron 
work  of  operating  boards  and  power  panels,  etc. 

Shellac:  For  covering  decks,  spars,  etc. 

Graphite  Paint:  For  painting  hot  parts  of  engines,  etc. 

Insulac:  For  preserving  insulation  on  electrical  instruments, 
etc. 

Q.  How  is  an  engine  painted  ? 

A.  All  hot  surfaces  should  be  painted  with  black  graphite 


EXAMINATION  OF   TORPEDO-COMPANY  GUNNERS.  189 

paint.  All  other  surfaces  after  being  thoroughly  scraped  and 
sand-papered  should  be  given  a  priming  coat  of  red-lead  paint. 
This  should  be  lightly  rubbed  down  with  powdered  pumice 
and  oil,  then  two  coats  of  preferably  steel  color  metal  paint  ap- 
plied and  rubbed.  Two  coats  of  varnish  are  now  applied  and 
rubbed  with  pumice  as  above,  after  each  coat  becomes  thoroughly 
dry. 


HANDLING  HIGH  EXPLOSIVES. 

Q.  Name  some  high  explosives  used  in  submarine  mining. 
A.  Wet    gun-cotton    principally,    dynamite,    and    other    high 
explosives  that  can  be  readily  purchased  in  commercial  life  in 
case  of  emergency. 

Q.  Why  is  wet  gun-cotton  to  be  preferred  as  a  high  explosive  ? 
A.  Because  it  is  perfectly  safe  to  handle.     It  can  only  be 
detonated  by  first  detonating  a  small  piece  of  dry  gun-cotton 
placed  near  it. 

Q.  What   are   some   important   precautions   to   be   observed 
when  loading  mines  ? 

A.  i°  Always  wear  rubbers  when  entering  the  magazine  to 
get  the  explosive.  (The  main  supply  is  always  kept  in 
a  cool  magazine.) 

2°  Never  drop  or  slide  along  the  floor  boxes  of  high  ex- 
plosive. 

3°  Do  not  expose  high  explosive  to  sun's  rays  or  heat. 
4°  Bring  only  one  box  to  the  loading-room  at   a  time, 
then,  when  used,  burn  the  box  and  sawdust  in  a  safe 
place. 
5°  Place  canvas  or  burlap  on  floor  of  loading-room,  then 

place  mine  on  skids  upon  this. 
6°  Use  rubber  gloves  when  handling  dynamite. 
7°  Sweep     floor    frequently    and     throw     sweepings     in 
water. 


190 


THE   GUNNER'S  EXAMINER. 


B°  After  mine  is  loaded  by  use  of  funnel,  carefully  clean 
threads  with  a  soft  brush,  then  smear  plenty  of 
ruberine  on  threads. 

9°  Never  .^aw  or  bore  a  dry  guncotton  cake. 
10°  Never  open  a  mine  loaded  with  dynamite  without  first 

consulting  an  officer. 

11°  Never  thaw  out  dynamite  near  a  stove. 
Q.  How  is  dynamite  that  is  frozen  thawed  out? 
A.  Place   the  frozen   dynamite   in   an  open  watertight  can. 
Place  this  can  in  another  can  of  warm  water,  such  that  the  heat 
of  the  warm  water  only  will  do  the  thawing. 

KNOWLEDGE    AND    USE    OF    THE     PLOTTING-BOARD     AND     AZIMUTH 

INSTRUMENT. 

Q.  Describe  the  plotting  board. 

A.  It  is  the  same  as  that  used  for  guns  except  the  gun  arm 
and  its  parts  are  not  used.  The  scale  is  ordinarily  100  yards  = 
i  inch. 

Q.  How  is  it  used  for  mine  firing? 

A.  The  ship  is  tracked  by  plotting  points  of  intersection  of  the 
primary  and  secondary  arm  every  20  seconds.  After  several 
positions  are  plotted  a  point  is  predicted  at  a  certain  interval 
of  time  ahead  and  by  means  of  a  ''combination  prediction  and 
speed  scale"  the  time  of  the  arrival  of  the  ship  over  the  mine 
which  was  previously  plotted  on  the  board  is  obtained  and  this 
is  the  time  of  firing  that  mine.  This  is  called  "judgment  firing." 

Q.  Describe  and  use  the  azimuth  instrument. 

A.  See  Examination  for  First-class  Gunners  for  Gun-com- 
panies. 

BATTERIES,   GENERATORS,   AND  SEARCH-LIGHTS. 

Q.  Name  the  batteries  used  in  mine  work. 
A.  Casemate  battery  (storage — 40  cells)  and  boat  telephone 
battery  (either  storage  or  dry  cells  sufficient  to  give  15  volts). 


EXAMINATION  OF  TORPEDO-COMPANY   GUNNERS.  191 

Q.  Describe  the  casemate  battery.  (See  Fig.  103.) 
A.  This  is  a  storage-battery  of  the  standard  chloride  accumu- 
lator type.  It  is  composed  of  40  cells,  type  D~5  (D  =  size  of 
plate  5,  the  number  of  plates).  D~5  has  two  positive  and  three 
negative  plates,  each  6"X6".  Positive  plates  are  of  a  brownish 
color,  negative  grayish.  These  plates  are  contained  in  a  glass 
jar  nearly  filled  with  electrolyte  (one  part  sulphuric  acid  to  five 
parts  distilled  water  by  volume  makes  electrolyte  of  1.210  specific 
gravity.  The  acid  must  be  poured  into  the  water.) 

These  glass  jars  are  placed  in  trays  of  sand  and  the  trays  rest 
on  glass  insulators.  The  normal  charge  and  discharge  rate 
of  this  battery  is  5  amperes,  although  in  starting  the  motor  gener- 
ator a  much  higher  current  is  drawn  from  the  battery.  The 
voltage  is  about  80. 

Q.  What  precautions  are  necessary  to  keep  it  in  order? 
A.  i°  Do  not  overcharge,  overdischarge,  or  allow  to  stand 
completely  discharged.     (Battery  should  be  charged  when  dis- 
charge is  1.8  volts  per  cell.) 

2°  Keep  plates  covered  with  electrolyte  about  f  inch  above 
top  of  plates.  If  not  at  proper  height  add  distilled 
water. 

3°  Keep  cells  free  from  sediment. 

4°  A  record  of  each  cell  (voltage  and  specific  gravity) 
should  be  kept  each  time  the  battery  is  charged, 
and  this  should  be  done  about  once  a  week. 
5°  The  indications  of  a  complete  charge  are :  when  positive 
plates  have  a  deep  chocolate  color,  negative  light 
slate,  cells  gas  freely,  each  cell  reads  about  2.5  volts, 
and  i. 2 10  specific  gravity,  and  when  no  perceptible 
rise  in  voltage  occurs  for  a  lapse  of  10  to  15 
minutes. 

6°  If  any  low  cells  develop,  bring  them  back  into  condi- 
tion immediately. 

(a)  If  voltage  is  very  low,  look  for  sediment  or  foreign 
matter,  then  charge  separately. 


THE  GUNNER'S  EXAMINER. 


EXAMINATION  OF  TORPEDO-COMPANY   GUNNERS.  193 

(b)  If  specific  gravity  is  very  low  take  out  some  elec- 
trolyte and  add  1.200  specific  gravity  electrolyte. 
(This  used  to  be  1.400.) 
7°  Keep    battery-room    well    ventilated,    especially    while 

charging. 

8°  Never  bring  an  exposed  flame  into  battery-room  while 
charging.  (The  gases  given  off  are  explosive  when 
mixed  with  air.) 

9°  Keep  the  floor  and  all  parts  of  the  room  clean,  iron, 
copper,  and  metal  work  free  from  corrosion;    keep 
all  connections  tight  and  clean;   never  allow  verdigris 
to  collect  anywhere. 
Q.  Describe  a  searchlight. 

A.  It  consists  of  an  iron  cylinder  mounted  on  an  iron  pedestal 
in  a  yoke.  The  cylinder  contains  a  parabolic  mirror  in  the  back, 
a  series  of  glass  strips  in  the  front,  and  two  " carbons"  in  the 
middle. 

The  electric  current  in  passing  through  the  carbons  heats  the 
points  to  a  very  high  degree,  producing  a  brilliant  light.  This 
light  is  reflected  by  the  mirror  towards  the  front,  and  the  mirror, 
being  of  a  curved  form,  also  converges  the  rays  of  light.  Under- 
neath most  searchlights  are  electric  motors  for  traversing  and 
elevating,  and  these  motors  are  started  or  stopped  by  means  of 
switches  in  a  contrivance  called  a  ''controller,"  which  is  always 
placed  at  a  distance  from  the  light. 

Q.  Point  out  the  following  parts  of  a  36"  searchlight:  hand 
star- wheel  for  slow  vertical  movement;  wheel  for  throwing  out  split 
nut  used  for  connecting  or  disconnecting  the  drum  from  the 
base  mechanism;  wheel  for  slow  horizontal  movement;  hand 
star- wheel  for  clamping  turntable  to  center-pin  for  electrical  con- 
trol; wood  handles  on  drum  for  moving  drum-  by  hand;  hand- 
wheel  for  clamping  hand  star-wheel  A  when  electric  control  is 
used;  controller-switch;  controller-handle;  controller  fuse- box; 
controller-coupling  for  connecting  cable  from  the  projector; 


EXAMINATION  OF  TORPEDO-COMPANY   GUNNERS.          195 

focusing-screw;  socket  for  inserting  wrench  to  operate  lamp- 
switch  used  for  cutting  out  feeding-magnet;  socket  for  inserting 
wrench  when  feeding  by  hand ;  door  used  for  adjusting  the  car- 
bons and  for  cleaning  the  front  door;  door  used  when  carbons 
are  to  be  adjusted  or  changed;  front  door;  door  used  when 
adjusting  negative  carbons  or  cleaning  the  mirror;  horizontal 
peepsights;  vertical  peepsights;  sliding  case  to  be  opened  when 
lamp  mechanism  is  to  be  inspected;  projector  main  switch; 
latches  for  fastening  base-sheeting;  base-sheeting. 

A.   See  Fig.  104. 

Q.  Describe  the  principal  parts  of  the  charging-generator  ? 

A.  The  frame  holds  the  field-magnets  within  which  revolves 
an  armature  consisting  of  a  winding  of  conductors  and  a  commu- 
tator. Brushes  made  of  carbon  touch  the  commutator.  The 
base  rests  on  guides  which  permits  of  a  motion  of  the  generator 
to  take  up  the  slack  of  the  belt. 

Q.  Point  out  the  following  parts  of  the  generator:  frame,  base, 
field-coil,  commutator,  brushes,  shaft,  pulley,  adjusting-screw, 
rocker-handle,  magnet-frame  bolt,  brush-holder,  brush  stud-cable, 
rocker,  bearing-cup,  journal-box,  pole-shoe,  pole. 

A.  See  Fig.  105. 

Q.  Point  out  the  following  parts  of  the  oil-engine :  cylinder- 
casing,  vaporizer,  vaporizer-cap,  vaporizer-cover,  vaporizer- cover 
lid,  valve-box  journal,  valve-box  sleeve,  spray-nozzle,  horizontal 
valve,  horizontal-valve  spring,  vertical  valve,  vertical- valve  spring, 
valve-box,  valve-box  screw-cap,  valve-box  coupling,  overflow- 
glass,  oil-pump  can,  oil-pump  plug,  oil-pump  plunger,  oil-pump 
plunger- spring,  oil-pump  plunger-head,  oil-pump  plunger-head 
guide,  oil-pump  gauge,  oil-pump  body,  bed-plate,  bearing-cup, 
splasher,  oil-tank,  oil-filter,  filter-cock  worm-gear,  gear-wheel, 
gear-guard,  crank-shaft,  crank-pin  oiler,  piston,  connecting-rod, 
cam-shaft,  governor- wheel,  governor- pinion,  governor-counter- 
poise, crank-shaft,  governor-balls,  governor-counterweight,  air- 
valve  cam,  exhaust- valve  cam,  cam  rollers,  cam  shifter,  locking- 


ig6 


THE  GUNNER'S  EXAMINER. 


EXAMINATION  FOR    TORPEDO-COMPANY  GUNNERS.         197 


I98  THE   GUNNER'S  EXAMINER. 

handle,   air-valve,    exhaust-valve,    cylinder-lubricatoi     cylinder- 
lubricator  pulley,  fly-wheel,  fly-wheel  key-guard,  splasher 
A.  See  Fig.  106. 

Q.  Name  some  important  points  to  be  observed  in  caring  for 
the  generator. 

A.  i°  Keep  it  perfectly  dry. 
2°  Keep  it  perfectly  clean. 
3°  Do  not  let  pieces  of  iron  or  steel  come  rear  it  when 

running. 

4°  Keep  the  belt  adjusted. 
5°  Keep  the  bearings  well  oiled. 

6°  Keep  commutator  clean  and  smooth  (use  fine  sand- 
paper only;  then  a  soft  cloth  and  some  oil  or  vaseline, 
then  dry  thoroughly). 

7°  Keep  brushes  in  trim  and  making  good  contact. 
8°  Do  not  allow  armature  to  heat  badly,  or  it  will  suddenly 

burn  cut. 

9°  Keep  brushes  on  neutral  point   to  prevent  sparking. 
There  is  usually  a  mark  on  the  dynamo  to  show  this, 
if  not,  rock  brushes  until  sparking  ceases. 
10°  Keep  covered  when  not  using. 
11°  Keep  connections  clean  and  tight. 
12°  Never  overload  it. 

CASEMATE    APPARATUS. 

Q.  Point  out  the  following  parts  of  the  power  panel: 

Milli -ammeter  and  its  protect-  Alternating  current  voltmeter. 

ing  lamp.  Double-pole  double-throw  lever 
Double  pole  circuit-breaker.  switches. 

Single  pole  reverse  current  cir-  Double- pole    single- throw    lever 

cuit  breaker.  switches. 

Direct  current    ammeter    (two  Receptacles. 

way).  Plugs. 

Direct  current  voltmeter.  Lamps. 


EXAMINATION  FOR   TORPEDO-COMPANY  GUNNERS.          199 

D.  C.  busses.  Resistance  for  reverse  current 

A.  C.       "  circuit- breaker. 

Charging  rheostat.  Terminal  strips. 

Field  Fuses. 

Fuse  clips. 

A.  This  must  be  learned  at  casemate. 

Q.  Point  out  the  following  parts  of  the  operating  panel: 
Signal-block.  A.  C.  jaw. 

Master     "  D.  C.     " 

Mine  Testing  switch  on  master  block. 

Cable  terminal  block.  Firing  switch. 

Single    stroke    gong    and    its       Jumper. 

switch.  Testing  switch  on  mine  block* 

Red  lamp  and  white  lamp,  and       Automatic  switch. 

use  of  each.  Mine  switch. 

Resistance  coil  and  its  use.  Power  switch. 

Earth  terminal.  Automatic  switch  release. 

A.  C.  Solenoid. 

D.  C.       " 

The  terminal  block  is  provided  with  binding  posts  and  clips. 

A.  This  must  be  learned  at  the  casemate. 

Q.  What  is  a  motor  generator? 

A.  A  combination  of  a  separate  motor  and  a  generator  con- 
nected to  the  same  shaft. 

Q.  What  kind  of  a  motor  generator  is  the  one  in  the  case- 
mate? 

A.  It    consists  of    a    motor  driven  by  direct  current  and  a 
generator  which  delivers  alternating  current.     It  has  about  i  J  H.P. 

Q.  WThat  is  the  voltage  of  each  ? 

A.   So-no  for  the  motor  and  about  the  same  for  the  generator. 

Q.  What  is  the  object  of  the  casemate  transformer  ? 

A.  To  raise  the  voltage  from  about  So  to  500  alternating 
current. 

Q.  Describe  the  mine  transformer. 

A.  This  will  be  learned  in  the  casemate. 


200  THE   GUNNER'S  EXAMINER. 

Q.  Explain  what  switches  you  would  set  on  power  panel  for 
automatic  firing,  the  board  having  been  previously  tested  and 
found  by  the  electrician  to  be  in  order. 

A.   i°  Put  D.  C.  on  busses 

(a)  Close   double-pole   circuit-breaker    (storage- 

battery),  or 

(b)  Close   S.  P.   reverse   current   circuit-breaker 

and  switch  No.  2  to  the  right  (post  power), 


by 


or 

1  (c)  Close  S.  P.  reverse  current  circuit-breaker 
and  switch  No.  2  to  the  left  (casemate 
generator) . 

2°  Read  voltage  by  plugging  in  proper  receptacle. 
3°  Close  switch  No.  3  up. 
4°       "  "   4  "  (or  down). 

5°      "         "        "   9"   ("      "  ). 
6°  Read  A.  C.  voltage  by  plugging  in  proper  receptacle. 
8°  Close  switch  No.  8  up. 

Q.  Explain  how  to  set  operating  panel  for  automatic  firing. 
A.  All    contacts,    connections,    switches,    etc.,    having    been 
previously  tested  and  examined  by  the  electrician  and  found  in 
order : 

i°  Close  up  the  testing,  automatic,  mine,  power,  and  gong 

switches. 

2°  Close  firing  switch. 

Note. — If  one  or  more  automatic  switches  cannot  be  made  to 
stay  up,  open  the  power  switch  for  that  mine  before  closing  firing 
switch. 

Q.  How  would  you  fire  by  judgment  ? 

A.  Conditions  being  as  above,  lift  the  automatic  switch  release 
of  the  mine  to  be  fired  at  the  command  "Fire  " 
Q.  How  are  mines  tested  ? 
A.   i°  Put  D.  C.  on  D.  C.  busses. 

2°  Open  power  switches  on  all  mine  blocks. 

3°  Unscrew  all  green  lamps  except  on  panel  being  tested. 


EXAMINATION  FOR    TORPEDO-COMPANY   GUNNERS.         201 

4°  Close  switch  No.  3  down. 

5°  Close  power  switch  of  each  mine  in  succession  and  read 
milli-ammeter.  This  should  be  about  30  to  40  milli- 
amperes. 

Q.  Point  out  and  describe  the  parts  of  a  boat-telephone. 
A.  See  Fig.  107. 

Q.  Describe  how  to  connect  up  and  use  the  boat-telephone. 
A.   i°  Connect    one   wire   of   the  casemate  'phone  to  either 
side  of  the  battery,  and  the  other  to  the  ground  (water- 
pipe  is  a  good  ground). 

2°  The  same  end  of  the  battery  is  connected  to  wire  Nos.  i, 
13,  or  19  of  the  multiple  cable  leading  to  the  dis- 
tribution-box boat. 
3°  Connect  one  wire  of  the  'phone  in  the  D.  B.  boat  to 

this  same  core  (No.  19,  for  example). 
4°  Connect  the  other  wire  to  an  earth  plate  which  is  over- 
board.    (An  earth  plate  is  usually  made  of  iron  or 
copper.) 

5°  The  other  terminal  of  the  telephone  battery  has  a 
permanent  connection  to  earth.  These  connections 
then  place  the  two  telephones  in  parallel  with  the 
battery. 

To  call,  press  the  push-button. 
To  talk,  press  the  talking-switch. 

Q.  Point  out  and  describe  the  parts  of  a  wall- telephone  com- 
posite artillery  type. 
A.  See  Fig.  108. 
Q.  Give  the  tests  for  telephones. 
A.  i  st.  Bell  is  not  rung  by  its  own  magneto. 
Analysis:  i.  Short  circuit  on  line. 

2.  Mechanical  trouble  in  the  bell. 

3.  Short  circuit  in  the  phone. 

4.  Open  circuit  in  the  phone. 

5.  Magneto  does  not  generate. 


202 


THE   GUNNER'S  EXAMINER. 


THE  BOAT  TELEPHONE. 

•Telephone  Leads 


Tranarrritteo 


FIG.  107. 


EXAMINATION  FOR    TORPEDO-COMPANY   GUNNERS 


203 


Operator's  test :  With  the  receiver  on  the  hook  turn  the 
magneto  handle  briskly. 

If  the  bell  does  not  ring  and  the  magneto  turns 
hard,  (I.  Short  circuit  on  line)  or  (3.  Short  circuit 
in  phone)  is  indicated,  and  the  operator  proceeds  as 
follows,  trying  to  ring  after  each  step : 

COMPOSITE  ARTILLERY  TELEPHONE. 


Induction  Coils. 
1000  Ohms. 


FIG.  108. 

Inspect  for  contact  of  lightning-arrester  carbons : 
a  piece  of  writing-paper  should  pass  between  them 
easily.  See  that  the  ends  of  the  line  and  ground 
wires  do  not  touch  any  other  part  after  passing 
through  the  binding -posts. 

Disconnect  the  line  and  ground  wires.  If  the 
bell  rings  now,  (i.  Short  circuit  on  line)  is  clearly 
indicated,  but  if  it  does  not  ring  and  still  turns 
hard,  (3.  Short  circuit  in  phone)  is  indicated. 


204  THE  GUNNER'S  EXAMINER. 

If  the  handle  does  not  turn  hard,  the  operator 
takes  up  (2.  Mechanical  trouble  in  the  bell)  and 
sees  that  the  striker  is  not  bound  by  the  metallic 
cap  over  it  or  by  the  wood  of  the  box,  also  that  the 
armature  can  be  moved  by  hand  and  that  the  striker 
will  touch  the  gongs  when  the  armature  is  so  moved. 
The  first  trouble  can  be  remedied ;  the  others  should 
be  reported. 

(4.  Open  circuit  in  the  phone).  Open  the 
magneto  box,  see  that  contact  is  made  between  shaft 
and  spring  at  U  and  between  the  springs  at  V 
when  the  handle  is  turned.  The  last  may  fail 
because  the  shaft  is  caught  at  some  place,  as  where 
it  enters  the  box  or  the  collar  on  the  shaft  may  have 
slipped  or  the  springs  may  be  bent.  The  spring  at 
U  may  be  held  against  the  end  of  the  shaft  with  a 
pencil,  during  a  test,  to  insure  good  contact.  A 
spark  seen  at  U  or  V  indicates  poor  contact.  If 
the  operator  cannot  easily  correct  these  faults,  he 
should  report  as  nearly  as  practicable  what  trouble 
he  found. 

Test  for   (5.  Magneto  does  not  generate)   by 
moistening  the  tips  of  the  fingers  and  touch  terminals 
of  magneto.     Turn  the  handles,  and  if  no  shock  is 
felt,  a  failure  to  generate  is  indicated. 
2d.  Bell  is  not  rung  by  distant  magneto. 
Analysis:  i.  Home  phone  out  of  order. 

2.  Distant  phone  out  of  order. 

3.  Line  out  of  order. 
Operator's  test: 

(a)  Test  for  (i.  Home  phone  out  of  order)  by 
detaching  the  line  and  ground  wires  and 
turning  the  handle. 

(6)  Test  for  (2.  Distant  phone  out  of  order) 


EXAMINATION  FOR    TORPEDO-COMPANY   GUNNERS.         205 

at  the  distant  phone  in  a  manner  en- 
tirely similar  to  (i.  Home  phone  out 
of  order). 

(c)   See  expert's  test  for  line  troubles. 
Can  hear  but  cannot  be  heard. 

Analysis:  i.  Local  circuit  at  fault. 

(a)  Battery,  (b)  connections  or  wiring, 
(c)  transmitter,  (d)  primary  coil. 

2.  Distant  receiver  out  of  order. 

3.  Home  secondary  coil  short-circuited. 
Operator's    test:    Disconnect   line   and   ground    wires 

and  connect  binding-posts  R  and  C  with  a  piece  of 
wire,  thus  short-circuiting  the  phone.  Place  the 
receiver  to  the  ear  and  scratch  gently  with  the 
finger-nail  on  the  inside  of  the  transmitter  mouth- 
piece. 

If  this  is  distinctly  heard,  the  local  circuit  and 
receiver  are  all  right. 

If  no  sound  results,  put  the  receiver  to  the  ear, 
lower  and  raise  hook  lever,  also  open  and  close  the 
two-way  switch.  If  a  distin  ctclick  is  heard  for  each 
of  these,  the  local  circuit  is  all  right  but  the  trans- 
mitter may  not  be  in  good  order  and  a  report  should 
be  made. 

If  no  sound  results  from  above,  make  sure 
that  the  switch  contact  is  good  and  no  pivots  are 
loose,  that  all  contacts  are  good,  that  the  connec- 
tions at  battery  terminals  are  good  with  no  green 
substance  on  the  wires  or  posts,  that  the  water  in 
the  jars  is  up  to  the  prescribed  point,  about  an 
inch  from  the  neck  of  the  cell,  that  the  zincs  and 
carbons  are  not  touching,  that  the  zincs  are  not 
eaten  off.,  and  that  the  zinc  of  one  cell  is  connected 
to  the  carbon  of  the  other,  and  that  there  are  no 
crystals  on  the  zincs  and  carbons. 


206  THE  GUNNER'S  EXAMINER. 

The  operator  should  correct  any  of  these  that  he 
can,  reporting  the  others. 

For  (2.  Distant  receiver  out  of  order)  the  opera- 
tor at  the  distant  phone  should  try  the  tests  above. 
If  these  give  no  sound  in  his  receiver,  he  should  try 
another  receiver,  if  one  is  available.  He  may  try 
a  new  cord  or  substitute  two  pieces  of  wire  for  it. 
3d.  Can  neither  hear  nor  be  heard. 

Analysis:  This  indicates  general  trouble: 

1.  In  the  phones. 

2.  In  the  line. 

Operators'  test:  Go  over  the  phone  carefully,  looking 
for  poor  contacts,  as  when  an  insulated  wire  is  put 
in  the  binding-posts,  binding-posts  not  screwed 
down  tight,  ends  of  wires  passing  through  post 
touching  other  parts,  contacts  at  cells  and  condition 
of  cells  as  noted  before.  Disconnect  the  line  and 
ground  wires  and  test  out  phones  as  indicated. 
See  that  ground  wire  is  in  the  middle  post.  If  there 
are  fuses  in  the  line,  see  that  they  are  not  burned  out. 
If  no  trouble  is  found  to  exist  when  the  l/.ne  is  dis- 
connected, report  line  out  of  order. 


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UNIVERSITY  OF  CALIFORNIA  LIBRARY 


